Why did my screen suddenly get this blue tint?

Ok, all of the sudden my computer screen just turned blue. There's a deep blue tint on the entire screen and it is really annoying. Why is this and how do I get rid of it?
Update: Just checked/unplugged and then plugged back in every wire on my computer and it's still blue. It's done this before and it sometimes goes back to normal, but then it comes back to this blue tint.
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