Some facts about color blindness
Someone who is color blind is often thought of as not being able to distinguish any colors at all - seeing the world in black, white and gray. In reality, the vast majority of people classified as being "color blind" can see colors, but they are often skewed or tend to blend together. Red-green color blindness is the most common form. It occurs in approximately 8% of the male population, 0.5% of the female population and accounts for 99% of all color blindness. After that is blue-yellow color blindness which is only present in approximately 0.01% of the entire human population. Total color blindness is a very rare and serious vision condition which inflicts roughly 0.003% of the entire human population.
|From Left to Right - Original Image, Deuteranope (red-green) Simulation, Protanope (blue-yellow) Simulation|
Now, here's an example. Most of you should be able to tell the difference in these images. I, on the other hand, have a hard time distinguishing the left and center images from each other at all and the rightmost image is just slightly different. As you can imagine, this kind of deficiency can throw a serious wrench in gaming since so many games rely on colorful iconography to relay important information.
Dealing with deficiency
In most cases, my red-green problem is just a minor inconvenience, but color blindness of any type presents a unique challenge for game designers and can become an issue for groups of players who have one or more color blind individuals among them. One of the best positive examples of this is the Ticket to Ride by Days of Wonder.
I won't go into a huge breakdown of the rules for Ticket to Ride, but there is a fair amount of color matching that needs to be done between the cards and the different train routes. In addition, each player has a unique set of colored trains that they use to mark who has claimed which route. It can be a huge mess and, in fact, I have a really hard time playing the mobile app Ticket to Ride Pocket because the greens and oranges tend to blend together. However, Days of Wonder has made the boardgame itself (and the iPad version of the app) much more color blind friendly by including shapes on the route spaces that correspond to shapes printed on the cards, making it easier for me to match them to each other.
Where shapes are impractical (perhaps your game has too much iconography as it is), then bright primary colors can succeed. Runewars by Fantasy Flight Games is a great example. The 4 different factions in this empire-building wargame are light blue, dark purple, red and green. Having a lighter blue against the darker purple makes them easier to distinguish from one another and the red and green pieces are colored using very stark, bright hues.
|A selection of components from the Runewars: Banner of War expansion|
Boardgamegeek is also chock-full of resources for various games to make them more color blind friendly. Usually, these take the form of reference sheets or alternate component lists. Last but not least, if you have any type of color blindness or know someone who does and it seems like a game company hasn't taken this into consideration, contact them! Most game companies appreciate any sort of feedback that will help them make future releases more attractive to prospective players.
Some helpful links
This humble article could have easily turned into a discourse on ocular genetics. The subject is pretty fascinating, so here are just a few links to websites where you can learn more!