Having been a federal lawman for some twenty-five years (more or less), I think some of these paint jobs should be illegal. The owners of some of these guns should be slapped by the fashion police - the same group who ticket fat women in hot pants and so forth.
I am forever amazed by the depths of nonsense to which the hoplophobes will descend in order to further the agenda.
To think painting a firearm will 'disguise' it in some fashion, how curious? The sad truth is various cops have - to their horror and sorrow - shot people with laser tag 'guns', cameras, TV controllers and wallets.
For that matter, no matter what it looks like, once the firearm is fired, the cat is out of the bag so to speak. If it makes a real loud bang, the coloration will not make much difference. (Happily, most bad guys are pretty rotten shooters and don't connect the first shot - a great blessing to lawmen of all ilks.)
Perhaps if I paint my automobile a drab color, the Highway 'Trolls won't think it will really go over the speed limit?