there are different ways of doing it.
You could use one of the many themes that FrontPage offers. Some of them are a tad vivid, but if you look through the selection you'll probably find one you like. You can customise your theme when you've applied it, so that your site has its own unique look. Themes can be applied to a single page, a group of pages, or the whole site, and include navigation bars and buttons, headers, fonts etc.
If you right-click on a blank page and select properties you'll be able to choose a background colour, or an image to use as a background.