I use white text and orange links on a black background for my surfing. How? In Firefox: Go to Tools-> Options-> Content tab-> Advanced button, Set the color chips, Uncheck "Use colors specified on web pages" To toggle this effect, get the nifty "toggleDocumentColors" Add-On for a toolbar CSS toggle icon (get it from the customize dialog for the toolbar)
In IE: Go to Tools-> Internet Options-> General tab Click "Colors" to set the color chips, Click "Accesibility Options" Check "Ignore colors present on webpages"
For Chrome: Find the application(C:\Users\Root\AppData\Local\Google\Chrome) Shift right-click to get a command line, and run it: chrome --enable-user-stylesheet
Then edit Custom.css (C:\Users\Root\AppData\Local\Google\Chrome\User Data\Default\User StyleSheets)