These days, you use Cascading Style Sheets (CSS). The easiest way to do this is to embed some CSS code
directly into the page itself, in the head section.
<Style type="text/css">
body {background-color: #FFEBCD}
</style>
Note, the color above is encoded ("#FFEBCD") in hexadecimal.... Go here to get the hexadecimal codes for your favorite colors.
Material taken from the CSS tutorial at W3Schools.