To specify the color, you must know the color's hexidecimal RGB (red, green, blue) value. If you can find the color's RGB number, you can convert it to hexidecimal using this handy convertor. There is also a Web page of popular color numbers to get you started.
In this example, the color OOFFFF is blue. You must specify the color number in the body tag like this:
<body bgcolor=#OOFFFF>
Click here to this page with the color in the
background
The tag for specifying a background uses the background= attribute with the path or URL to the image. If you create your own image and have it in the directory with the html file, you can just specify the image name.
<body background="metal.gif">
Click here to see this page with the background