Light-weight blogging platform Posterous has finally catch up with its competitor Tumblr by [offering custom theming](http://blog.posterous.com/posterous-theming-its-here-its-live-and-its-t). You can now ditch the yellow-and-white Posterous theme. Five built-in themes are available for you to choose from, with color pickers to change the colors of your blog, and you can upload an image to customize the header.
For the more adventurous, you can overhaul the look with custom CSS and HTML. And the theme is Tumblr compatible, you can just drop your Tumblr theme codes into the theme editor. Click here to view the [Custom Themes documentation](http://posterous.com/theming).