Here's something I came up with to help those who absolutely have to have a black dock. Since Apple moved from image files to CoreGraphics rendering code, the only way to customize the color of the dock is to modify the code.
It can be quite complex as it involves some hacking of the OS, but as I wanted a black dock bad enough to do this, I figured there may be others.
Automatic Method UPDATED:
Coded a program that should handle it for you without the need for any extra tools or files. It performs a static decryption on the file and removes an integral part of the code signature to bypass the signing process rather than fake codesigning the binary as I did in previous versions.
Consider this BETA software, and post if you have problems, and I will try to improve it.
Code:
usage:
dockmod -c <color> -r
-c, --color color to make the dock ('default' or 'black')
-r, --noreflections disable icon reflections
Keep in mind, again, this will only work for 10.8.2 so far, and will have to be updated for future versions.
use it like this:
The color options are "black" and "default" for the -c option, and the -r option will disable icon reflections.
This is what it looks like: