If you don't use a background image, you can specify a background colour using the attribute BGCOLOR="#??????" where ?????? is a hexadecimal number. These colours can also be applied to other things such as text, links, active links and visited links. There are also 16 preset colours where you can enter a name instead of the hex number.

Aqua = #00FFFF
Black = #000000
Blue = #0000FF
Fuchsia = #FF00FF
Grey = #808080
Green = #008000
Lime = #00FF00
Maroon = #800000
Navy = #000080
Olive = #800080
Purple = #800080
Red = #FF0000
Silver = #C0C0C0
Teal = #008080
White = #FFFFFF
Yellow = #FFFF00