Hi teqtaq,
Go on your form and go into design view. Here if you right click and go on Properties (alternatively: View->Properties) you can change the background colour and effects. To choose a colour click in the Back Color box, and then at the right most edge will be a small button with three dots, click this and then choose your colour.
You can change the style of writing aswell, click on a label, etc, and then choose any option from the formatting toolbar. If this is not open, right click at the top on a toolbar and make sure "Formatting" is selected (alternatively: View->Toolbars->Formatting).
I am currently changing the design of a form, and this is about as much as I know, but if I come across anything else, I will post a reply and let you know.
Hope this helps,
Andrew