To create a theme on XMB login as administrator. Click on Options-Administration Panel. There, under Look and Feel, click on themes. On the next page, scroll down. Under the list of existing themes you’ll see a link that says New Theme (next to it are links saying the following “Check All”, “Uncheck All” and “Invert Selection”). Once you click it a page will show up where you pick the colors and other details of your new theme. Fill it out and you’re done!