How do I create a Google Chrome Theme (CRX file)?

How do I go about changing the look of Google Chrome? I hear you need to create a CRX file but I don't know where to start. I want an image as the background and some different colors.|||Your easiest option is to use an online editor such as http://www.themechrome.net which is really good. You can pick a wallpaper from a huge collection and quickly tweak your color scheme. Then download in Google Chrome and it will automatically install and apply. Easy peasy.