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ASTRO BOY
2012-Dec-21, 09:43 PM
Simple enough question and probably appears on face value quite mundane.
But this question on another forum provided many hundreds of pages and many threads of debate.

OK here were the main two arguments.
[1] The colour of an Orange in the dark is still Orange......
a property of the surface which makes it absorb certain wavelengths of light.
then the orange still is orange.


and this.....

[2]The Orange in the dark has no colour.....The colour of any object in the first instant depends on the type and frequency of the EMR that falls upon it.....


I agree with the second option.
What do people here think?

Paul Beardsley
2012-Dec-21, 10:23 PM
Lawful neutral.

Oops, wrong thread.

I agree with 2. The real question is, what do you call it while it isn't orange? There's no such fruit as a nocolour.

Solfe
2012-Dec-21, 10:41 PM
I would say it is orange until the light levels fall below the requirement for colored sight. Then you don't have any color perception at all and the question becomes moot.

Hlafordlaes
2012-Dec-22, 12:54 AM
I dunno, but I can hear it falling.

Wolf1066
2012-Dec-22, 01:09 AM
its colour is "soft with a slightly stippled texture"...

Jeff Root
2012-Dec-22, 01:27 AM
Both answers [1] and [2] are correct and necessary.
But not sufficient.

An orange (or anything else) has certain physical
properties which determine how it will reflect, refract,
diffract, emit, absorb, and otherwise affect light which
falls on it. The properties could change when light
actually does fall on it. Some dyes fade over time
when exposed to ultraviolet light, for example.

Naturally, the color of the object also depends on the
light which actually falls on it. An orange illuminated
by red light would be red. An orange illuminated by
green light would be green. An orange illuminated by
blue light would be dark gray or black. An orange
illuminated by red and green light would be some
shade of orange.

Depending on the visual receptors of the observer.
If the observer can only see green and blue light, he
will never see an orange as orange. He could only
see it as green.

If a lightbulb is emitting orange light, it doesn't much
matter what colors of light it reflects or what colors are
falling on it. The orange emitted light is what makes it
orange, and what makes it *look* orange when eyes
with the necessary receptors and brain processing look
at it while it is hot. If it isn't hot, it won't be orange
and won't look orange.

What color an object is depends on:

[1] Physical properties of the object
[2] Wavelengths/frequencies of light involved
[3] Capabilities of the visual systems involved, if any

-- Jeff, in Minneapolis

Swift
2012-Dec-22, 02:40 AM
This does not appear to be a question of science, but of philosophy, so the thread is moved from S&T to OTB. If someone wishes to dispute that, Report this post and give an explanation.

jokergirl
2012-Dec-22, 08:26 AM
"At night, all cats are grey."

I never understood that adage, having a black cat.

;)

ASTRO BOY
2012-Dec-22, 09:07 AM
Both answers [1] and [2] are correct and necessary.
But not sufficient.

An orange (or anything else) has certain physical
properties which determine how it will reflect, refract,
diffract, emit, absorb, and otherwise affect light which
falls on it. The properties could change when light
actually does fall on it. Some dyes fade over time
when exposed to ultraviolet light, for example.

Naturally, the color of the object also depends on the
light which actually falls on it. An orange illuminated
by red light would be red. An orange illuminated by
green light would be green. An orange illuminated by
blue light would be dark gray or black. An orange
illuminated by red and green light would be some
shade of orange.

Depending on the visual receptors of the observer.
If the observer can only see green and blue light, he
will never see an orange as orange. He could only
see it as green.

If a lightbulb is emitting orange light, it doesn't much
matter what colors of light it reflects or what colors are
falling on it. The orange emitted light is what makes it
orange, and what makes it *look* orange when eyes
with the necessary receptors and brain processing look
at it while it is hot. If it isn't hot, it won't be orange
and won't look orange.

What color an object is depends on:

[1] Physical properties of the object
[2] Wavelengths/frequencies of light involved
[3] Capabilities of the visual systems involved, if any

-- Jeff, in Minneapolis

Won't argue with any of what you have said, other then to say that in the first instant, the colour of anything depends on the EMR falling on it.......the other points then kick in.

boppa
2012-Dec-22, 11:58 AM
Simple enough question and probably appears on face value quite mundane.
But this question on another forum provided many hundreds of pages and many threads of debate.

OK here were the main two arguments.
[1] The colour of an Orange in the dark is still Orange......
a property of the surface which makes it absorb certain wavelengths of light.
then the orange still is orange.


and this.....

[2]The Orange in the dark has no colour.....The colour of any object in the first instant depends on the type and frequency of the EMR that falls upon it.....


I agree with the second option.
What do people here think?

So who are you at the good doctors forum Astro boy?

may the original forum rip...

swampyankee
2012-Dec-22, 12:48 PM
"At night, all cats are grey."

I never understood that adage, having a black cat.

;)

Black is just a very dark grey.

Hornblower
2012-Dec-22, 03:14 PM
"At night, all cats are grey."

I never understood that adage, having a black cat.

;)

That refers to light-colored cats as seen in dim light in which our color vision fails. Under those conditions, depending on the background, your cat might be invisible except possibily for its eyes.

Buttercup
2012-Dec-22, 03:24 PM
It's still orange.

Lack of light wouldn't change its actual color; only how we perceive it.

Jeff Root
2012-Dec-22, 03:31 PM
Lemme ask...

Buttercup,

What is color?

-- Jeff, in Minneapolis

Buttercup
2012-Dec-22, 03:38 PM
Lemme ask...

Buttercup,

What is color?

-- Jeff, in Minneapolis

We both already know.

The color of the orange's flesh itself doesn't change due to presence or absence of light.

Otherwise not going to get drawn into these sorts of debates. :)

Perikles
2012-Dec-22, 03:49 PM
The color of the orange's flesh itself doesn't change due to presence or absence of light.I have a small tree in my garden which has half a dozen very green oranges on it. They have been green every day for at least a month, and I have no reason to believe that they stop being green every night just because it gets dark.

DonM435
2012-Dec-22, 04:11 PM
Depends upon how you define "color."

It may be defined as an inherent property of the object; or it may be defined as a property of the sight receptors in the eye.

In the first case, it's orange until somebody paints it another color or something. In the second, it isn't any color until you look at it.



Like when the umpire was asked "Well? Is he safe or out?"

"He ain't nothin' until I call it!" was the reply.

The player assumed that safe/out was an inherent property. The ump favored the idea of the perception, and he's in charge.

cjameshuff
2012-Dec-22, 05:09 PM
Approximately that of a 300 K black body.

Jeff Root
2012-Dec-22, 05:13 PM
Chris wins.

-- Jeff, in Minneapolis

Jeff Root
2012-Dec-22, 05:30 PM
Lemme ask...

Buttercup,

What is color?
We both already know.
You really don't want to say things like that if you
don't want to get drawn into whatever sort of debate
this might be.

Since I'm not sure I know, either you more about what
I know than I do, or you were wrong about what I know,
in which case I'd like you to tell me.

Please. What is color?



The color of the orange's flesh itself doesn't change due
to presence or absence of light.
Ah. Okay. Interesting. So, what is color?

-- Jeff, in Minneapolis

Paul Beardsley
2012-Dec-22, 05:49 PM
I think it's fair to say Jeff nailed this one in post 6.

Any further comment is probably a quibble over definitions. Just as we can agree that the metal known as mercury is a liquid at room temperature... but so is iron if the room is warm enough! This is why "room temperature" has a specific meaning in a scientific context.

Colour* has a generally understood meaning in its everyday use, and so does orange**. When someone asks what colour an orange is normally, it's understood to mean a ripe orange in something like natural light as viewed by a human with fairly normal eyesight and not wearing sunglasses. Given this, the OP's question is a bit of a cheat (a bit like discussing a tripod with a missing leg), but a useful cheat in that it encourages us to question our assumptions. Which is healthy.

*Color in the US
**Alani in Hawaiian

Chuck
2012-Dec-22, 06:29 PM
Dictionary.com says "1. a globose, reddish-yellow, bitter or sweet, edible citrus fruit." An orange isn't orange at all.

Jeff Root
2012-Dec-22, 06:36 PM
I thought that by now I had seen every entry in my
(ink on paper) dictionary. Apparently not.

-- Jeff, not at all globose in Minneapolis

DonM435
2012-Dec-22, 08:10 PM
So, was the fruit named after the color or vice-versa?

If it's closer to red or to yellow, is it still an orange? (Actually, they're green before they ripen.)

ASTRO BOY
2012-Dec-22, 08:18 PM
The "Colour" of any object depends on two things.....the type and frequency of the EMR falling upon it and secondly the reflective properties of the object itself.

If we took an Orange [or anything of colour] to a planet orbiting a star that shone primarily in the green part of the spectrum [or any other frequency you care to name] that object would appear a different colour then on Earth.

Another example. In festive mode in Sydney at night the white shells of the Sydney Opera House are sometimes bathed in laser light of different colours. The inherent property of the shells [that appear white under sunlight] reflect that colour so that the shells are able to appear green or red or blue.

But the reflective properties of any object depends on the frequency and type of EMR falling on it.

So therefor I deduce that the colour of an Orange [or any thing] in the dark is black....or in other words it has no colour.

ASTRO BOY
2012-Dec-22, 08:25 PM
I think it's fair to say Jeff nailed this one in post 6.

Any further comment is probably a quibble over definitions. Just as we can agree that the metal known as mercury is a liquid at room temperature... but so is iron if the room is warm enough! This is why "room temperature" has a specific meaning in a scientific context.

Colour* has a generally understood meaning in its everyday use, and so does orange**. When someone asks what colour an orange is normally, it's understood to mean a ripe orange in something like natural light as viewed by a human with fairly normal eyesight and not wearing sunglasses. Given this, the OP's question is a bit of a cheat (a bit like discussing a tripod with a missing leg), but a useful cheat in that it encourages us to question our assumptions. Which is healthy.

*Color in the US
**Alani in Hawaiian



In probably agreeing with that assessment and Jeff's earlier on, we still cannot get away from the fact that in the first instance, the colour of any object depends on the EMR falling on it.

Paul Beardsley
2012-Dec-22, 09:15 PM
In probably agreeing with that assessment and Jeff's earlier on, we still cannot get away from the fact that in the first instance, the colour of any object depends on the EMR falling on it.

That was part of post 6.

Moose
2012-Dec-22, 10:37 PM
It's grey.

The tree falling in the forest one is easy enough. For it to be a sound, rather than just a vibration, one also needs a medium and a receptor; something to perceive it as 'sound'.

The same principle applies to color. Orange is how we perceive a certain wavelength of light acting against our cones. If the light level is insufficient to trigger our cones, yet just sufficient to trigger our rods, we perceive the 'color' as a shade of grey. So in the dark, an orange is grey.

ASTRO BOY
2012-Dec-23, 09:19 AM
The same principle applies to color. Orange is how we perceive a certain wavelength of light acting against our cones. If the light level is insufficient to trigger our cones, yet just sufficient to trigger our rods, we perceive the 'color' as a shade of grey. So in the dark, an orange is grey.


Sorry, I've done that experiment in a complete darkened room and the Orange is black...that is it has no colour.

Jeff Root
2012-Dec-23, 01:07 PM
Don,

The color seems to be named after the fruit. The name
of the fruit comes from the Farsi word "narang".

-- Jeff, in Minneapolis

grapes
2012-Dec-23, 02:27 PM
Dictionary.com says "1. a globose, reddish-yellow, bitter or sweet, edible citrus fruit." An orange isn't orange at all.
It's not orange, it's reddish-yellow?

cjameshuff
2012-Dec-23, 02:35 PM
It's not orange, it's reddish-yellow?

I had a similar reaction to that statement. Chuck, did you read dictionary.com's definition of the color orange, a bit further down the page?

Chuck
2012-Dec-23, 03:20 PM
I guess they're trying to avoid using the word being defined in its own definition.

DonM435
2012-Dec-23, 03:25 PM
How does one define colo(u)r?

We can't seem to agree on how to spell the word!

DonM435
2012-Dec-23, 03:27 PM
Don,

The color seems to be named after the fruit. The name
of the fruit comes from the Farsi word "narang".

-- Jeff, in Minneapolis

Thanks. I wonder what the color was called in regions where the fruit was unknown?

grapes
2012-Dec-23, 03:49 PM
It wasn't rangpur...

swampyankee
2012-Dec-23, 07:02 PM
Thanks. I wonder what the color was called in regions where the fruit was unknown?

I've read a few (Internet) articles about the linguistics of color names. Very weird to a horridly monoglottal Anglophone, but the red-orange-yellow-green-blue-indigo-violet (plus brown, grey, black, white, etc) of English is not universal.

Jeff Root
2012-Dec-24, 02:46 AM
I might as well post my list of color names. Checked but
not yet double-checked to eliminate duplicates and be sure
color names belong where I put them. This list is cleaner
and more complete than any I could find when I compiled it.
A few terms are deliberately in more than one group. The
most basic and common terms are genrally near the start
of each group.

COLOR NAMES IN ENGLISH

BLACK:
jet, ebony, raven, midnight black, ink black, blue-black,
obsidian, onyx black, charcoal, soot, licorice, antique black,
blackcat black, gothic black

WHITE:
alabaster, porcelain, ivory, chalk, bone, eggshell, milk-white,
cream, linen, ecru, antique white, off-white, pearl, hemp, wheat,
bisque, natural, navajo white, latte, snow white, virgin white,
crisp white, paper white, sugar white, pure white, winter white,
ice, glacier, cloud, birch, diamond, opal, lotus, oyster, silver,
platinum, champagne, lamb, iceberg, flake white, titanium white,
almond, blanched almond

GRAY (GREY):
taupe, pearl gray, dove, charcoal, slate, gunmetal, steel gray,
iron gray, plumbago, lead, silver, chrome, platinum, pewter,
Oxford gray, heather, cement, flint, pebble, storm, soot, ash,
smoke, cinder, putty, fossil

RED:
ruby, rouge, garnet, carmine, cinnabar, vermilion, crimson,
madder, alizarin, maroon, magenta, scarlet, cardinal red, rose,
burgundy, wine, beet red, cherry, strawberry, cranberry, apple,
tomato, cordovan, adobe, brick red, blood red, fire engine red,
candy apple red, Chinese red, Indian red, Tuscan red, lipstick red,
Revlon red, fire red, flame red, torch red, sunset red, matador
red, fiesta red, true red, really red, raspberry red, sherry red,
chili red, claret red, jelly bean red, peppermint red, persimmon,
Persian red, auburn wine, poppy, hibiscus, cinnamon, paprika,
tomato bisque, lobster bisque, steaming, american beauty,
geranium, atom red, artillery red, ashes of roses, shrimp,
winter apple, oxblood, carnelian

PINK:
baby pink, ballet pink, blush, rose, rose petal, orchid,
coral, salmon, peachblow, pink carnation, european pink,
hot pink, shocking pink, neon pink, fuchsia, magenta,
schiaperelli pink, pink flamingo, bubblegum, Pepto-Bismol,
cadillac pink, peppermint pink, cotton candy, cherry candy,
tickle me pink, pretty in pink, peachy pink, barbie pink,
strawberry ice cream pink, pink lemonade, pink sherbet,
old fashioned pink, pastel pink, powder pink, dusty pink,
ice pink, ashes of roses, baby's skin, shell, shell pink,
petal, blossom, geranium, azalea, begonia, tea rose, haze,
watermelon, raspberry, strawberry, raspberry sorbet

ORANGE:
rust, russet, saffron, peach, coral, salmon, tangerine, mango,
papaya, persimmon, apricot, cantaloupe, melon, pumpkin, carrot,
mandarin, burnt orange, poppy, adobe, harvest moon, neon orange,
fluorescent orange, sunset, traffic cone orange, garfield orange,
orange sherbet, orange crush

BROWN:
tan, taupe, auburn, hazel, henna, fox, fawn, amber, cordovan,
maroon, oxblood, russet, rust, copper, bronze, umber, sienna,
burnt umber, burnt sienna, chocolate, cocoa, coffee, cappuccino,
latte, java, coffee bean, espresso, cafe au lait, cafe noir,
toffee, toast, cinnamon, nutmeg, burnt almond, acorn, chestnut,
walnut, maple, oak, mahogany, redwood, resin, golden brown,
woody, putty, greige, claret, bordeaux, brandy, cognac, bourbon,
sherry, peat, adobe, clay red, terra cotta, saddle, antique brown,
bracken, havana, partridge, truffles brown, hemp, dark soapstone,
maple sugar, pigskin, hacienda, classic clay, aztec, california
gold, molten copper, brickstone, seal, coconut, rich earth,
caramel brown, earth brown, Van Dyke brown

BEIGE:
ecru, bisque, cream, taupe, khaki, sand, camel, fawn, chamois,
champagne, wheat, buff, shell, sandstone, barley, oatmeal, flax,
putty, clay, pebble, grain, mushroom, almond, cafe au lait,
bare beige, canvas beige, cord beige, flax beige, french beige,
smoky beige, biscuit tan, oakleaf, spanish moss, nacre, string,
sahara sand, praline cream, ancient amber, pearl bisque

YELLOW:
canary, saffron, ochre, straw, flaxen, blond, amber, brass,
gold, chrome yellow, cadmium yellow, topaz, citrine, citron
yellow, lemon, banana, maize, mustard, butter, butterscotch,
honey, cornsilk, sunflower, marigold, primrose, buttercup,
daffodil, goldenrod, crocus, jonquil, old ivory, sunshine
yellow, neon yellow, mellow yellow, curious yellow, powder
yellow, paris yellow, tuscan gold, lemon meringue, lemon drop,
lemon sherbet, lemon chiffon

GREEN:
emerald, jade, turquoise, kelly, hunter, olive, olive drab,
khaki, peridot, chartreuse, lime, shamrock, grass green,
apple green, celery green, chive green, asparagus, spinach,
sea green, seafoam green, caribbean green, alpine green,
canton green, chrome green, acid green, jadestone, boxwood,
moss, evergreen, crystal green, mystic green, blue-green

BLUE:
navy, sapphire, royal blue, electric blue, sky blue, baby blue,
powder blue, robin's egg, cornflower, cerulean blue, azure,
turquoise, lapis lazuli, cyan, blue-green, teal, slate blue,
steel blue, periwinkle, indigo, cobalt blue, ultramarine, aqua,
aquamarine, marine blue, ocean blue, sea blue, pacific blue,
glacier blue, ice blue, copen, copenhagen blue, delft blue,
Wedgwood blue, Oxford blue, Tiffany box blue, Alice blue,
chambray blue, Prussian blue, French blue, Capri blue, Limoges
blue, alpine blue, Caribbean blue, midnight blue, twilight blue,
neon blue, cadet blue, air force blue, denim blue, blue jean,
sonata blue, hyacinth, rocket blue, peacock blue, forget-me-not
blue, iris, blueberry, moody blue, smurf, blue lake, bahaman,
tahiti, haze, storm, gentian, bluebird, monaco, bermuda, yale,
empire blue, williamsburg, brilliant blue, sistine, mermaid,
spring sky, asian aqua, waterlily, cobblestone grey, ming

PURPLE:
violet, magenta, indigo, mauve, plum, royal purple, fuchsia,
amaranth, heliotrope, lavender, lilac, heather, amethyst, wine,
burgundy, port, grape, raisin, berry, mulberry, boysenberry,
blackberry, eggplant, beet, orchid, iris, pansy, hyacinth,
wisteria, thistle, concord, claret, aborigine, londonberry,
brandywine, rajah, candy orchid, purple haze, slurple purple,
wild grape, grape kool-aid, grape crush

-- Jeff, in Minneapolis

DonM435
2012-Dec-24, 04:29 AM
I remember how the great book Science Made Stupid defined "The Risible Spectrum" as colors like mauve, ecru and puce.

Jeff Root
2012-Dec-24, 04:44 AM
Okay, I need to add "puce" to the list...

-- Jeff, in Minneapolis

Hornblower
2012-Dec-24, 12:44 PM
Sorry, I've done that experiment in a complete darkened room and the Orange is black...that is it has no colour.

I would refine that experiment with an orange and a lime side by side on a black velvet background, and look at them in a dark place under white light shining through a pinhole to make it very dim, but still enough to make the objects visible against the darker background with my eyes fully dark adapted.

swampyankee
2012-Dec-24, 01:10 PM
More fun with color terms: http://www1.icsi.berkeley.edu/~kay/color.terms.lx.of.ps

As a comment on the OP: in the dark it's still the same color; it's the perception of it that's changed. Since I happen to believe that there is an objective reality, I think that the color of the orange is independent of our ability to perceive its color.

Perikles
2012-Dec-24, 01:30 PM
As a comment on the OP: in the dark it's still the same color; it's the perception of it that's changed. Since I happen to believe that there is an objective reality, I think that the color of the orange is independent of our ability to perceive its color.That is how I would view it as well. In that case, I'm not so sure about this:


The tree falling in the forest one is easy enough. For it to be a sound, rather than just a vibration, one also needs a medium and a receptor; something to perceive it as 'sound'. .If the tree creates sound waves in the air, it seems to me that a receptor is not required. The physical event is the same whether somebody is there to record it or not.

swampyankee
2012-Dec-24, 01:48 PM
If the tree creates sound waves in the air, it seems to me that a receptor is not required. The physical event is the same whether somebody is there to record it or not.

I agree. Unfortunately, this gets serious with quantum effects, where some people seem actively to believe that an intelligent observer is needed to cause a quantum event to become defined. I think this is blatant nonsense, as I think the interpretation that the diffraction pattern which occurs in double-slit experiments where one photon passes through the apparatus at a time implies that each photon "knows" where it should go. Also nonsense; there's a probability the photon goes on a given path.

Moose
2012-Dec-24, 02:29 PM
If the tree creates sound waves in the air, it seems to me that a receptor is not required.

Hold your breath and place your head underwater in a wave pool. The moving wall creates 0.3~ hertz compression waves passing through you. Since the frequency of these waves are well below what humans can hear, you hear only the background noise of the motors. The background noise of the motors includes a tone at 2000Hz. Other than frequency and amplitude, these waves are mechanically identical.

But only the latter is a sound.

[Edit: Basically, this is an argument that rests entirely upon the precise physics definition of 'sound'. You're absolutely right in that, other than the presence or absence of a receptor and perceiver, the mechanical event is identical.]

Perikles
2012-Dec-24, 02:56 PM
[Edit: Basically, this is an argument that rests entirely upon the precise physics definition of 'sound'. Agreed. Your example of different (sound) frequencies means that a 40,000 Hz wave is not sound to me, but is sound for my dog. I think I would find it neater to say compression waves of all frequencies are sound, only a part of which humans can hear, parallel to electromagnetic waves often being called light waves, even outside the visible spectrum.

Moose
2012-Dec-24, 05:26 PM
Agreed. Your example of different (sound) frequencies means that a 40,000 Hz wave is not sound to me, but is sound for my dog. I think I would find it neater to say compression waves of all frequencies are sound, only a part of which humans can hear, parallel to electromagnetic waves often being called light waves, even outside the visible spectrum.

I'd say both definitions have validity depending on context. The problem I have with the OP philosophy question is the same problem I have with the "tree in the forest" question. They're barely meaningful as it is, and they lose even that meaning when you discard the distinction between what we perceive and what we don't.

Ultimately, both questions boil down to: "Does perception matter?" And the answer to that, again, depends on how you frame the question. "Does [perception matter] in how we classify and model the universe around us?" Clearly, yes. "Does perception shape literal reality?" Clearly, no.

Jens
2012-Dec-25, 02:55 AM
As a comment on the OP: in the dark it's still the same color; it's the perception of it that's changed. Since I happen to believe that there is an objective reality, I think that the color of the orange is independent of our ability to perceive its color.

What if you're looking at an orange in a black and white photograph? Would you still say it's orange? Personally, I think this is really a question of semantics and not reality, i.e. what we mean by "color".

Solfe
2012-Dec-25, 06:00 AM
What if you're looking at an orange in a black and white photograph? Would you still say it's orange? Personally, I think this is really a question of semantics and not reality, i.e. what we mean by "color".

I had to do this very project in an art class. It is basically a paint mixing exercise. Paint an object in color, then mix black and white paint to the exact same tone but without the hue. Usually the whole thing is done side by side, so you can see where you went wrong.

Another project is mix two colors together to make a different hue, then mix the color opposite it across the color wheel. If you have done both operations well (not really "correctly") then the resulting mix will tend to be gray. Typically, this doesn't work and you end up with browns.

I don't know why brown is the usual outcome, but artists try to avoid painting "muddy" in reference to the fact. Personally, I find the resulting gray colors to be equally ugly to the browns.

Jeff Root
2012-Dec-26, 09:33 AM
Another project is mix two colors together to make
a different hue, then mix the color opposite it across
the color wheel. If you have done both operations
well (not really "correctly") then the resulting mix
will tend to be gray. Typically, this doesn't work and
you end up with browns.

I don't know why brown is the usual outcome, ...
Weird coincidence. I was thinking about that a few
hours ago.

I discovered when I was in first grade that drawing
over yellow crayon with violet crayon makes brown.
Brown is essentially a dim yellow or orange. Orange
can be just light in the orange part of the spectrum,
in which case it likely won't be very bright, or it can
be a mix of red and yellow or red and green light.
Yellow, in turn, can be just light in the yellow part
of the spectrum, in which case it also likely won't be
very bright, or it can be a mix of red and green light,
like on a TV screen.

Yellow crayon on white paper reflects mostly red,
orange, yellow, and green light. Adding violet crayon
apparently dims that to brown as its main effect.

Here's my web page on colors:

http://www.freemars.org/jeff/colors/

-- Jeff, in Minneapolis

Solfe
2012-Dec-26, 05:10 PM
Weird coincidence. I was thinking about that a few
hours ago.

I discovered when I was in first grade that drawing
over yellow crayon with violet crayon makes brown.
Brown is essentially a dim yellow or orange. Orange
can be just light in the orange part of the spectrum,
in which case it likely won't be very bright, or it can
be a mix of red and yellow or red and green light.
Yellow, in turn, can be just light in the yellow part
of the spectrum, in which case it also likely won't be
very bright, or it can be a mix of red and green light,
like on a TV screen.

Yellow crayon on white paper reflects mostly red,
orange, yellow, and green light. Adding violet crayon
apparently dims that to brown as its main effect.

Here's my web page on colors:

http://www.freemars.org/jeff/colors/

-- Jeff, in Minneapolis

Neat! I have a color page (http://www.pretendertothepower.com/?page_id=603) on my website for oil painting.

SeanF
2012-Dec-26, 05:40 PM
What if you're looking at an orange in a black and white photograph? Would you still say it's orange?
I would not say the photograph is orange, but I would still say the orange was.


Personally, I think this is really a question of semantics and not reality, i.e. what we mean by "color".
I whole-heartedly agree.