Turns out, there is a ticket open in the Maven JIRA project for this, but so far, there doesn't seem much traction, and fixing it for me now would involve forking Maven again, which I'd rather not. Therefore, I decided to take the Greasemonkey approach and write a wrapper around the Maven output so that I can format it exactly how I want.
Introducing the Console Colorizer, a command line tool for wrapping Maven execution, then feeding its output through a Lexer that adds VT100 color codes where appropriate. This approach is suprior to the usual colorizing the logging output, because I can match any text and highlight it any way I want. Going a bit farther, I could even detect certain bits of output and execute arbitrary code, like sending a Growl or IM notification. All this without modifying any Maven Java code.
Compare this raw Maven 2 output:

With this:

It is so much easier to see that the test failed, and what warnings your Maven plugins are complaining about. This tool works by wrapping the Maven main execution and running the System.out through a JFlex lexer. The lexer is nice because it allows me to define tokens via regular expressions, yet remain very fast and compact. A few VT100 codes allow me to add the coloring.
Of course, this same technique could be applied to any Java program, or any program at all if you really wanted to, but for now, I think it'll do nicely to clean up Maven 2 a bit.