Style sheets are explained here:
http://www.htmlgoodies.com/tutors/ie_style.html

And there is a very complete list of style sheet references here:
http://builder.cnet.com/Authoring/CSS/table.html

Here is a good site with Hex Colour referencing:
http://www.htmlgoodies.com/tutors/colors.html

Or if you need RGB colour combinations (like for Microsoft image composer):
http://www.phoenix.net/~jacobson/rgb.html

This one talks about the colours that won't dither on a 16-colour pallet
(useful):
http://www.webdiner.com/annexe/hexcode/hexcode.htm