You may have seen this:

I had debugger syntax highlighting working before, but I overcomplicated it and never figured out how to approach the problem.

I was inspired to try again by Mithaldu's post about augmenting the debugger. Once I realized that I had a much better strategy than previously, the code was straightforward.

I tested it on 5.12.2. I offer no guarantees. It's on Github as DB--Color. You don't like it? Fix it :)