CSS has the 6 prime colours, plus dark versions of each of them, plus black, white, silver and gray. CSS2 adds orange. The naming is unusual: pure green (i.e. #00ff00) is called "Lime", and the dark version of that is called "Green". Magenta is called "Fuchsia" and cyan is called "Aqua". Hover over the fields below to see the dark version. Styling stolen from Tantek