diff-colorize is a simple utility that syntax-colors and syntax-highlights unified (diff -u) and git-style (diff --git) diff output.
The default settings require an xterm running in 256-color mode. To achieve this, set your TERM environment variable to “xterm-256color”.
Apple's Terminal does not support 256-color mode. You will have to use 16-color mode. The default TERM value is xterm-color, which means that you are already using 16-color mode.
You can customize the colors by setting variables in your environment. Run the program with no input for more information.
Here's a larger screenshot that shows the program in active use (linked to a full-size image):
MD5 and SHA1 signatures were created using OpenSSL 0.9.7l.
If you want to contribute bug-fixes or enhancements to diff-colorize, the easiest way to do that is to clone the Mercurial repository for diff-colorize. To do this, type this command into a terminal:
hg clone http://bitbucket.org/boredzo/diff-colorize
I provide diff-colorize—the application, and its source code—under a three-clause BSD license. For more information, see the file named LICENSE.txt that comes with it.