The colour scheme you chose may be pre-determined by your existing corporate colours, perhaps you have a logo or established colour scheme which already defines your business or organization. If not the world is your oyster.
Two or three main colours are usually sufficient for the various design elements of a website including navigation bars and buttons, headings and text. Click here for an online tool to help chose colour schemes.
The key elements in any website design are:
Careful choice of style for the first three of these elements can complement the theme of the website, the colour scheme creates an atmosphere before the visitor has absorbed any of the messages which are conveyed by the actual content of the site. See below for examples of how the feel of a page can be transformed by swapping the colours.
This is a simple centre column layout with top and side menu bars which don't expand, I've used this design to demonstrate the effect which different colour schemes can create without changing the basic design.