Dear Windy,

as Dan said in his post you may change the hex-code of the background.
If you are not familiar with hex notation (00 hex = 0 decimal, FF hex = 255 dec), you may opt for using the rgb-method of CSS as well. Colors are given as a triplet of red/green/blue with decimal values (range 0 to 255) or percentages (range 0% to 100%).

Examples:

#top {background: rgb(255,0,0); }
#top {background: rgb(100%,0%,0%); }

give red, whereas

#top {background: rgb(255,192,192); }
#top {background: rgb(100%,75%,75%); }

I would call [color=#ffc0c0]pink[/color]...