I just get annoyed when people start getting all preachy about what is right and wrong based on real life demands that are almost entirely irrelevant in airsoft. As you say, at the ranges we deal with the colour of the weapon is of little significance other than looking gucci. Not there's ANYTHING wrong with that, but let's not try and dress it up for more than it actually is.
I stopped posting on the 501st Garrison forums for that very reason, everyone seemed to have lost sight of the fact that we were arguing over minute details of what a stormtrooper looked like "in real life". On a forum dedicated to grown men dressing up in white plastic armour from Star Wars. FFS.