Originally Posted by BlueMoon

I have a slightly abnormal colorvision, I couldn't pass the Ishira color vision plates they used in e office at my first medical. I went to an eye doctor and did a different color vision test and passed it (the FAA accepts like 15 different types and some are more/less discriminating than others), mailed that stuff to the FAA and I got a nice letter from them saying 'take this letter to all future medicals and this will serve as proof of your colorvision' (I'm paraphrasing).

Do that and take that letter to your airline medical. I have a slight color blindness to shades of green (according to the doctor)...didn't know about it for 20 years...and still don't notice it (Red buttons look red, Yellow buttons look yellow)