This useful site has great ideas about color and designing Web sites.
This is a useful chart of the hexadecimal code for colors on the web. It comes up quickly and displays the hexadecimal numbers in the colors they represent.
This site is the Webmasters color gallery, it allows you to select any color you wish to view and then gives you all the colors in which it was made. It is really a good web-site for a developers page.