As a comic reader I will add a few things that make this extra WTF-y, and try not to give any spoilers, LOL.
If we follow with Flash comic lit, The Flash can actually travel through time. And in the case of Barry's mother's murder in-comic, that is what happened - Reverse Flash went back in time to kill her. In Flashpoint (right before the New 52 came out) Barry went back in time and stopped his mother from dying which basically Marty McFly'd everything and stuff got weird. There's more but it's really too geeky, ultimately everything is set straight which means Barry's mom more or less has to die.
Cisco said red and yellow, Barry saw red and yellow. Yellow is the Reverse Flash, the red is - my guess - Barry, back in time with Reverse Flash, trying to stop him from killing his mother. But ultimately he either fails or chooses not to stop him because of the Marty McFly effect.
Some people have guessed the red might be Jay Garrick, since he was the original speedster, but so far I don't think there's any real evidence to suggest we'll meet Jay. Although I would appreciate that!
I still don't think it's who we think it is. Because it is too obvious and it doesn't fit with the comics, and we DID get a hint in the show that it will keep with the comics ("Why didn't he kill me?" "I don't know." OOH OOH I THINK I KNOW.) There's a possibility who we think it is is NOT who we think HE is - in other words, his name is not his real name...
So given that the Flash (and Reverse Flash) can travel through time... that opens up a handful of options, doesn't it?