I wanted to try to submit some links to this site, but decided to pass on this one because of FOUR major problems with their study:

1) although the study excluded color-blind people from participating (???), they mislead people into thinking it's a great color scheme for the general population

2) they said the color combinations differ for common fonts besides Arial, so it's not a good rule of thumb

3) computer LCD monitors could very well make green text on a yellow background very hard to read even for people with normal vision

4) The effects of reading very long pieces of text were not tested

Reasons #1 or #3 alone means I would not use that color combination without further testing with color-blind people as well as on older LCD screens. (Note, the study is down at the moment so I can't double-check what I said.)

Unfortunately, usability is as much about practical use as anything else and so if green text on yellow increases readability but bores most users to leave the site it's bad usability:)

-Zaid

It just looks horrible. Usability is not plan readability. There's an esthetic component to it as well.