I don't play airsoft, so the the muzzle of my M1A does not have an orange muzzle. However, it is my favorite "long gun".
A mere 12 pounds empty, and 28-1/2 inches long with the stock folded, it still should only be fired with the stock deployed.
I could paint the whole thing orange, and most people still couldn't figure out what it was. This whole color thing has just added to the confusion, which is why "kiddie" guns like water pistols are now transparent plastic.
Orange muzzle or not, the whole concept has been violated so much in both directions that prudence dictates treating everything you see as real. This is what happens to crooks and punks who think they're being smart. It's the same principle as sticking your hand in your pocket, and pretending it's a weapon. You can still be legally killed just as dead.