I’m sure you’ve seen them — backgrounds so loud and busy that your eyes almost pop out of their sockets just trying to read the text on the page. You often wonder if the authors have ever tried to read their own pages. It should be obvious why this is not a good idea; if visitors are unable or find it difficult to read your page, then they will not be staying long. While creativity and spontaneity may inspire some interesting creations, it is best to leave psychedelic art to those who share a common interest with Timothy Leary.
Make sure that you have enough contrast between the background and foreground (text) colors; low contrast is hard to read. Using blue text on a black background is not a good idea, as is using yellow on white. Also, light-colored text on a dark background is harder to read than dark text on a light background. Think about the real world; people are used to reading black text on white page. Doing the opposite every so often may add emphasis, but too much is not a good thing.
If you use background patterns, make sure that the pattern does not interfere with the text. Some patterns may look interesting on their own, but can make it difficult to read the text you put on top of them. For those who insist on using background images, try to decrease the contrast and increase the brightness of these images in an image utility like PhotoShop.
When in doubt, ask a friend or co-worker to review your pages. Because of your knowledge of the content and the text, you may not realize how difficult it may be to read your pages. Someone who is not familiar with the content will make a better judgement whether the colors are too close or if your background pattern interferes with the text.