There are all sorts of programs available to help with graphics, as well as ready-made material for free on the Internet. Later on I'll give some clues as to where to look and what to use. You will be able to use essentially any colour as background on your site that you might like. In addition, there are all sorts of textured backgrounds available. We'll look at these later, but it's something to begin thinking about.
Languages can be a problem.
Many Christians want to include information dealing with Scripture, and want to provide work in the Biblical languages. You'll need to be careful using Greek and Hebrew. As a matter of fact, it would probably be better if you transliterated rather than using the actual languages. The reason is that some browsers don't produce languages well. In addition, many laymen don't read the Biblical languages.