what happened is that you turned the "christmas colours" setting on, i think it's straight up stupid that they put that setting in the new gopro but what can we do? The problem is for some reason yours is recording pink instead of red, I think you may also have turned the "Valentines coliurs" setting on without turning the christmas one off. Take the gopro's battery out and then turn it back on, it should clear the issue up.
This is pretty much what has happened, sometimes I do enjoy the look though.
Another reason could be that the gopro casing had frosted up due to water freezing over the top on them cold days, happened to me a few times, just make sure its wiped/ licked off so the case is clear again.