I was originally going to say that color can be useful and should be allowed without restriction, but... after reading Corion's post I have to agree that while I (and many others) use the default theme, there's a pantload of people who use alternate themes. (Hey Vroom, are there any statistics?) I like the example tags and would use them if they existed. We'd just need to come up with colors in good taste for each theme.

Your Humble Servant,
-Chuck