Why does this one star look like it's blinking colors?

I was just on my telescope (Meade) when I saw a star, above the big dipper (the big dipper is upside down right now, Northeast Pennsylvannia at nine thirty four PM, which makes it lower on the horizon). I aimed my telescope at it, and saw a star that flashed vibrant colors, mainly red and blue. I'm kind of creeped out right now, becuase I don't recall any star being able to do such a thing. So what is it?