This thread may seem pointless at first, as there is no built-in preference pane that allows to change the boot screen. However, a developper has made the BootXChanger app, which allows for easy customization of both the image and the background color shown when booting. Here is mine, Aqua Blue with a custom "Happy MacBook Pro" icon I just made. Looks very much like it did 10 years ago, when Mac OS 8.6 was the best around. EDIT: obviously posting a screenshot will require some basic photo editing work, but nothing too much for most. I have included this icon and others I made (except the Happy Mac which I only enlarged).