One of the tremendous benefits of the Mac has always been the degree of customization that you can apply to your environment. Icons, sounds, graphics, and color can make your computer truly your computer. The following hints let you exceed the standard tricks and create a unique operating environment.
Behind the initial login screen, the background image is blue with some white arcs running through it in a semicircular pattern. It’s very attractive—the first 4,000 times you look at it.
If you’d like to express your creativity by replacing this background with something groovy and personal, try this technique:
Because you’re altering the screen everyone sees before login, this change affects all account holders on the Mac.
Choose an image you’d like to use.
Any JPEG is fine, though there’s no point in using an image that’s larger than your display area.
In the Finder, open the Library → Desktop Pictures folder.
A list of the standard Apple desktop images appears. Aqua Blue.jpg is the file you want to replace. Drag it out of the folder to a safe place as a backup (or just rename it).
Drag your own graphic into the Desktop Pictures folder. Rename your file Aqua Blue.jpg.
This sleight-of-hand allows the system to find it during the startup process.
If you don’t have a file in this folder called Aqua Blue.jpg, Mac OS X simply uses a solid blue background for the login screen.
Log out to bring up the login panel.