Black backgrounds are not always such a good idea. They are appropriate in very few cases. You need to have a really neat color scheme or graphics on a page to get away with a black background. Lets face it, a text page just does not look good on black. If it did then we would have books, magazines, and newspapers printed on black paper. Try to make sure that your colors won't clash if someone has forced their background color to black and foreground colors to white. Always set all colors. Hopefully, the viewer has either not set any browser colors or set all browser colors.