This is fascinating to me, actually, because not only am I a photographer, but I'm also colorblind to a degree. I'm referred to as red/green colorblind, but that's not what I experience. My trouble is between green and brown. For example, I can't tell what's brown or green in camo. I can tell both are there, but that's my mind convincing me both are there because I know they should be. To me they just look like different shades of the same brown.
Or green. Dammit I don't know which one it is.