In my short time using Mac OS X, I've come to love it. But something that bothers me about it is the inability to customize system colors. I like the colors for the most part, but there are some times when I'd like to be able to change them. For example: the Dock has a sleek, shiny silver color by default, but thats not something most people know how to change. This could make the dock look washed out against a dark desktop, or hard to see against a lighter one. Changing the Dock color is not a menu option, because Apple likes all their machines to look similar. But, since you're reading this, I guess you want yours to be different. You're in the right place!
You'll notice how difficult it is to see the Dock background against my beautiful automobile wallpaper.
Step 1: Locating the System Folder.
Did you know the Dock is an application?
This is convenient for certain modifications we might want to make to the appearance.
So, let's start off by locating Dock.app
It's not as simple as a Spotlight search, mind you. You'll want to open up a Finder window, and navigate to your startup disk. (If you don't know what this is, you probably left the name as "Macintosh HD") You'll see a folder called "System". Go ahead and open that up.
Step 2: Open the Contents of Dock.app
You're inside the System folder. Open "Library", which is the only folder there. You should be able to locate a folder called CoreServices, this folder should have the same icon as the System folder itself. When you open that, you'll see a blue and grey icon with the word "Dock". Right-click this and then select "Show Package Contents". You're getting close!
Step 3: Find Your Dock Image, Change It Up.
So you're inside the Dock, so to speak. Be careful in here, as accidentally deleting or changing anything is DANGEROUS. I am not responsible for any damage you do to your system. If you carefully follow the instructions, everything should be fine, but I make no guarantee.
Anyway, you'll observe that there are 3 images entitled scurve-something within the folder "Resources". Based on the quantity of icon content in your Dock, you'll need to select one of these. Sm means small, m means medium, l means large, and xl means extra large. Once you determine which one is for you, you need to copy it twice to a backup location, wherever you choose really. Just a place that you can keep a backup copy in case you want to change it back. So once you have your 2 copies, open one of them in your favorite image editor. I used iPhoto just to edit the tint, but you could use GIMP or Photoshop if you wanted. When you're done editing that, replace the original with the edited one in the Contents window. You're done! When you reboot your Mac, or kill the Dock, you should see your changes! Here's what I did to mine.