only with dark colors? I think a lot of us have trouble with navy and black but I also can barely tell the difference between brown and dark green. When you get into the brighter colors, though, like medium and light blue, I can see the different shades. Reds are pretty easy, too. Anybody else?
Have you ever been tested formally for colorblindness? There are actually several varieties. Myself, I have deuteranamolous trichromacy, which is a fancy way of saying I don’t see green as well as someone with color normal vision, but I still do perceive that color.
People who have the “-anamolous” in their type of color blindness see the affected colors best when they’re “saturated”, that is, very bright, and will have trouble with pastels and with very dark hues.
Your reference to trouble distinguishing brown and dark green *might *indicate you also have this condition, but maybe not. At a certain point everyone has trouble distinguishing colors.