This article suggests that colour blind gamers are forgotten by game developers. According to the article games often rely on colours to differentiate between characters, for example the good guys might wear green and the bad guys brown. This seems to pose a problem with people who are colour blind and the article quotes one of their readers who says:
“One specific gaming example that always frustrates me is Battlefield 2142. I love the game, but the flags of the two teams are not distinct enough on the HUD, at least to me. I honestly can’t tell you what color they are. Red, green, yellow, brown?” he told Ars. “I usually end up trying to distinguish them by brightness because one looks slightly brighter to me, but that is so slight it’s still tough.”
This was confirmed by my husband who is colour blind and says he has the same problem with several games. The solution according to the article is to use more drastic contrasts between colours and to use patterns and shapes rather than relying on simply making things two different colours.