For those of us who are Firefox users, spend a lot of time on this site, and would like to customize the background colors, font styles, sizes and colors there is a way to do so without it being too strenuous. Here's how to do it:
Click Tools in the Firefox menu bar, then select Options. On the Options popup window, select the Advanced button to customize the font style and size. Be sure to uncheck the box that says "Allow pages to choose their own fonts, instead of my selections above." To change the colors, return to the Options popup and select the Colors button to customize the colors on your screen. Be sure to uncheck the boxes that say "Allow pages to choose their own colors, instead of my selections above" and "Use system colors." Click on the various color buttons to bring up a color chooser box for each variable.
When you want to return to the default colors for this and other websites, just check those same boxes that you previously unchecked.
Here is a screen shot of a warmer color scheme example that may be better for some:
It isn't perfect, but might help dull the harsh "whiteness" that is bothersome to some.
Remember, you have to uncheck and check those boxes to switch between your customized colors and the default colors of the sites you visit.