When designing web sites, many graphic artists over-design forgetting a little-known fact: Around 5% or male Europeans or Caucasians have some sort of color blindness. For most of them it is only a small hindrance, but in some conditions it can become quite annoying. For example, when a web designer relied too heavily on color and made the web site nearly impossible to use by this large segment of the population.
I found a good web site that will help you determine if you are color blind and which will support web designers trying to make their web sites better: WeAreColorBlind.com. They are even providing patterns that show how best to use colors in this context.
If you want more support, I also recommend a visit to Chrometric, a web site where you will be able to freely download a tool to test your web site against various kinds of color blindnesses (you know that not all people have the same kind of insensitivity to colors, don’t you?) and allow you to test various solutions or improvement you may have designed.
For example, my other web site, www.YLovePhoto.com as seen by 6% of the male population: