Mine were gunmetal gray. I have lots of silver sim tools too - i've owned 2 or 3 of every iPhone since the original (except the 5c).
As for those devices, (and I can't believe I'm arguing with you - I suppose you don't believe in global warming either), they have ample non-metallic surfaces to allow radio waves in and out. For example, in the original iPad mini to which you refer, the wifi/bluetooth antenna is located in the chin near the speaker. There's pretty much just glass surrounding it in one direction, no metal.
No **** Sherlock -- that wasn't my point. I am saying that there does not need to be any WINDOW cut out in the metal casing for signals to travel through -- in other words, an iPad or iPod touch can, and have been, made with completely metal shells and receive wifi signals just fine. If people would be more astute they would recognize that the inserts are not plastic. They would scratch like the 5C, which has a "scratch resistant" coating. They are a liquidmetal alloy. Believe what you will, but you won't get anywhere trying to convince me otherwise.