IPhone 4 spazzed and now it won't do anything?

I was facetiming and I went to switch to a text and the screen completely freezes and it's like that for awhile and I try to turn it off but it wouldn't so I unplugged it from the charger and the screen slowly starts turning purple and when all of the screen is purple it starts to fade to black and now it won't shut off or work again. I tried holding down home and the power for awhile but it still won't shut off.

Go to apple and tell them that