[Crash] Screen turns pink and computer crashes during League games.

I have recently switched video cards and I assume the crash is related to that but I can't figure out why. I can play other games just fine but when I play League I, seemingly randomly, have my screen turn black to pink and then my computer crashes. Not a BSOD just total lockup. I have to hard restart and then everything seems fine. I only get this once a day(EDIT : Have had this happen more than once a day; It just happened nearly back to back.) I have been punished by LeaverBuster and been put into lower priority queues once already and I'd prefer I didn't get some sort of temp or permanent ban for something I can't control.