Don’t like the boring background colors of Outlook Express? To change it launch the Windows Registry Editor and scroll down to the
HKEY_CURRENT_USERSoftwareMicrosoftInternet Mail And News key.
On the left pane, click on ColorCycle or select Edit and Modify in the menu. Now change the value to 1. Close and restart. Now, launch Outlook Express and whenever you open up a New Message, hold down ctrl-shift and tap the z key to scroll to change the background color. Repeat the keystroke to cycle through the colors.