How to Solve It

Alternate vision modes could potentially enable a large audience of new players. Color blindness and low vision are not rare conditions -- the former affects roughly one in ten men, whereas low vision is harder to quantify (but consider the number of people who wear glasses or contact lenses...). Settings that allow for high-contrast visuals or alternative color schemes can give these players access to a game that would otherwise be impossible for them to play.

One guideline that has been suggested is never to use color contrast as the only way to convey information[md]so if something has to be red and green, make sure it's shaped differently or has a distinctly different look to it as well. Games that use power bars often use "green" for full health and "red" for poor health, which can be problematic -- but color blind gamers can at least use the length of the power bar as a cue in these instances.