Here is a Web site that shows you what various Web pages look like to people who have different types of color blindness. This is no small issue. Consider how many people are looking at the Web sites you worked so hard to design, and they do not see anything like what you put up there. The site says:
In the U.S. 7 percent of the male population -- or about 10.5 million men -- and 0.4 percent of the female population either cannot distinguish red from green, or see red and green differently. Color blindness affects a significant amount of the population, and it is even more prevalent in more isolated populations with a smaller gene pools. It is mostly a genetic condition, though it can be caused by eye, nerve, or brain damage, or due to exposure to certain chemicals.
Use the
Color Blind Web Page Filter to see how any site appears to people with different types of the condition.