I’ve read online that protans (people with protanopia or protanomoly, which is what I have) don’t see yellow as well, which I’ve never experienced, but I believe because yellow is a subtractive color made up of red and green. I’ve never experienced it with orange either but that’s a color not used very much, same with yellow.

Protans have dysfunctional red receptors in our eyes, so anything composed of red is gonna be a bit dull compared to some people. I say “dull” because my colorblindness is only mild; I can still see red, just not as much as most people (though it’s actually pretty common due to genetics in AMAB people).

The most common colors for protans to mix up are the following: red and green, pink and grey, and blue and purple. Mixing up red and green makes Uno a lot of fun (/s). Most of the time I’ll need to hold a red and green card right next to each other to see which is which. When I’m only holding one of either color I can usually tell which it is, though sometimes I’ll accidentally place a red card on a green and the table will be like “wrong color” lol. Pink and grey is a bad mixup cuz I can’t cook meat; I can’t tell if it’s done or still raw (obviously bad for meat like chicken), though these days I don’t eat meat so this isn’t a problem for me anymore. As for blue and purple, there aren’t a lot of circumstances where those colors are together, but when they are I usually need to see them side by side to tell which is which.