You will need to create a background in Fireworks to place on your pages. Remember to keep the theme of your region in mind when you are creating it. You also want to keep in mind that the background needs to subtle so that it does not distract viewers from your the text on the page. You can also experiment with placing your text in a table if your background is too abstract. When you have completed the background place it on each page. Remember, place the code in the body tag as follows:
<body background="nameofyourbackground.gif">