I think people stay away from green sometime because it looks to "stock". I mean, nearly every case had/has a green power led, along with CDROMS, floppies, keyboard, speaker, and monitor leds..
I personally think that green themes look really good though, like green and black.
This time I'm going with black and blue (Lian Li). Didn't want to get silver becuase it wouldn't match all my other stuff, and I dont see as many Black Lian's.