This is not that great idea. Both too little and too much information is bad.
I've already experienced it in practice in NetBeans 6+ where there was so much information (not just colors but various types of underlines etc.) that the code just looked like a rainbow and was hard to focus. I had to disable half of the features to be able to work again.
(Interestingly there were more issues with the newer NetBeans versions that I decided at one point, screw it and downgraded to NetBeans 5.5 and it was the best decision for my productivity in Java, I use it to this day).
I've already experienced it in practice in NetBeans 6+ where there was so much information (not just colors but various types of underlines etc.) that the code just looked like a rainbow and was hard to focus. I had to disable half of the features to be able to work again.
(Interestingly there were more issues with the newer NetBeans versions that I decided at one point, screw it and downgraded to NetBeans 5.5 and it was the best decision for my productivity in Java, I use it to this day).