To be fair, anyone waving an airsoft rifle around in the street deserves to get nicked. We all try for our guns to be as badass and realistic looking as possible, so its not really on to wave it around, terrify people and expect them to know what it is.
All that aside......just buy a good rifle, get it two toned. If you buy from patrol base or land warrior, then they two tone it very nicely. They pretty much guess it will be changed and only do a few big easily changed bits.
Then, apply power spray, soak and strip. If you dont like hard work, buy kraylon, and then spray it. Leave it to dry and harden over a few days, and put it back on the gun.