Interesting topic. I'm one that absolutely relies on my colour vision for my career - I'm a printer. I've taken far more colour-blindness tests than I care to remember; of several different types. I was interested to see how the familiar old Ishihara test fares online - it doesn't come close to the real thing. I agree with the others - if you're worried about colour-blindness (and no real reason you should be unless you have my job
) go to a specialist.
Out of curiosity I took the online version - about a year ago - of the CAT variant; a test in which you have to arrange coloured discs in order; the same one I had to take to get this job. IIRC I scored 96% in 6 minutes total for 4 trays (which is exceptional) for the real thing. The online version scored me at half that at almost 10 minutes - a failing grade. I'd say the online tests are a novelty; but little more.
Cheers!
"The difference between theory and practice is that in theory, there's no difference."
"Aikido: the art of hitting people with planets."