Thought it looked a bit strange and the ones on amazon don't look like that either (the red one there, for example)
I think the red one is tape and the seller may have stuck it on it himself. But I don't see anything that speaks against whether it is fake or not. The home button looks a bit suspicious to me, but that may be due to the light. They are normal silver (at least for me)
You can ask the seller yourself what the red one is all about