In MW2's multiplayer, the fastest way to differentiate friend from foe is if their name is green (teammate) or red (enemy). These colors also are used to to distinguish combatants on the game's radar. Colorblind gamers are asking for the ability to change friend/foe colorations so they can game without confusion.
The petition points out that Call of Duty: World at War had the option of changing enemy/friendlies from red/green to orange/blue. "The Ghost Recon games have also had a similar feature. With this being such a huge release, this option should come as standard, especially when almost 10 percent of people are affected by colour-blindness in some form."
I realize that when fewer than one in 10 men deal with this kind of vision (and half of one percent of women) we're absolutely talking about optimizing for a minority. The game is built, it's selling like nuts, updates cost money, and I'd be astonished if Infinity Ward rolled a patch for an affected population this small. And honestly, you grow up colorblind, you learn workarounds for the condition (on the traffic signal, top means stop, low means go.)
But, to future devs, red and green are the most commonly transposed colors in colorblindness. Pick a different pair, and you won't have us colorblind tugging on your pants leg with these kinds of frivolous-sounding demands.
For those curious, in that image the colorblind are supposed to see a number 17. Everyone else should see a number 15. I can't see shit.
MW2 Patch for Color Blind Gamers Urged [Game Politics]