Theoretically it would matter, since the 'acid test,' so to speak, in defining whether it is a RIF is whether determining whether it was a real gun or an airsoft gun would require someone to closely inspect the gun itself (the assumption being that if it was all bright orange and someone saw you with it they would 'know' it was a non-lethal toy). If adding sights, scopes, torches, etc. adds to its 'realness' then they add to its 'RIFness.' But this is a ridiculous 'test' since nobody walking down the street with an M4 is going to be ignored if the police officer who turns up can see that the M4 is "principally" orange!
Anyway, back to the point. It doesn't matter to you (if you are an airsofter) whether it is 51% unrealistically coloured or not since it is not illegal for you to manufacture or own a RIF. If anyone says: "where did you get that?" Tell them it's none of their business. If an officer of the law asks, then tell them where you got it since you've done nothing for which you are not legally 'covered.'
So stick all the accessories or whatever you want onto your gun since, as an airsofter who can prove he is an airsofter if required to do so in order to create a defence against prosecution, you are entitled to do what you want with it. As others have said, just don't be a dick with it and nobody will ever know or care.