Translucence

Translucence is a flexible, customizable theme that allows you to create a blog with 1-3 sidebars. Translucence provides options for setting the opacity and color of different areas of your blog.When the opacity for a given area is at 100%, that area’s color is simply whatever you specified. However, if the opacity is set to 50%, then the background color begins to appear in that area.

Translucence also allows you to link to your own background image.