The professional interface artists at Apple use Adobe Photoshop, just like professional artists everywhere else. But in Mac OS X, they've made very little effort to cover their tracks. In Cocoa programs and even a few Carbonized ones, every element of the famous Aqua interface is nothing more than a Photoshop-generated graphics file.
The beauty of graphics files, of course, is that you can edit them. Maybe you just want to adjust the colors. Maybe you found a replacement graphic online. Or maybe you actually want to draw a new graphic from scratch. In each of these cases, by using a program like Adobe Photoshop or Photoshop Elements, you can dress up your own desktop in your own way.
In addition to a little artistic talent, all you need to know is how to open the graphics that constitute the interface of each program. The routine generally goes like this:
In the Finder, open the Applications folder. Control-click (or right-click) the icon of the program you want to edit; choose Show Package Contents from the shortcut menu.
You may remember from Chapter 5 that most Mac OS X programs may look like single icons, but are actually disguised folders containing all of their own support files.
You can choose almost any Cocoa program to edit in this way:Address Book, Chess, iChat, Mail, iPhoto, Safari, iDVD, iMovie, TextEdit, whatever.
Open the Contents→Resources folder.
Inside are the objects of your search: the graphics files (often in TIFF or PDF format) that constitute ...