I was watching trace output flow across a console window when I had the thought that it would be much easier to see warnings and errors if they were color coded. I started off to write a color version of ConsoleTraceListener but decided a quick Google search was in order to see if this had been done. Sure enough, I quickly found a clean implementation from Joshua Flanagan. His site has a good usage example with screenshots.
http://flimflan.com/blog/ASimpleColorConsoleTraceListener.aspx