Yesterday I pointed out that OS X Leopard actually looks BETTER on old hardware because some of the fluff is turned off. This obviously implies that there is some hidden internal setting for controlling the fluff. Well, someone has found that setting! With a simple terminal command you can now get the nice solid Menubar on any Mac. Just fire up a terminal and enter the command (all on one line):

sudo defaults write /System/Library/LaunchDaemons/ 'EnvironmentVariables' -dict 'CI_NO_BACKGROUND_IMAGE' 1

You can only do this from an administrator account and you’ll have to enter your password. The command won’t have an immediate effect. You have to reboot your Mac to see your new and improved Menubar. I’ve tested this on my G5 PowerMac and my MacBook Pro, it seems to work flawlessly.

You can get more details in this ars technica article.