Comment by xiphmont

I would guess that's because some earlier remotes used a higher frequency IR emitter that was in fact touching into the red.

These days, the various IR communication protocols have been standardized and virtually all use 920nm, 940nm or 980nm emitters, all of which will be invisible. I mentioned the Apple IR remote specifically because it's a remote most people reading TFA will have, and it's known to be a 980nm emitter.