It's the camera's warning for bright and dark areas. Page 203 of the manual tells you how to turn it on and off for "playback", when you're looking at the photos you've already taken. Page 144 tells you how to turin it on and off in Live View. Page 249 tells you how to turn it on and off for "instant review", the image that shows on the display right after you've taken each photo.
Your actual photos aren't recorded with blinking areas. The camera is trying to warn you about possible exposure issues. So you probably don't want to turn all of the settings off. With digital images, overexposure means no detail is recorded for that part of the image. For that area, each color that the camera can see has the maximum value. The camera can highlight these areas for you to tell you those spots will have no detail. Let's say you're at a wedding and the display shows most of the bride's dress blinking. She will be very annoyed at you for not showing all that expensive detail.
The other colors mean something but I'm still trying to figure that part out. I just got a new K-7 and that was on my list of "what the hell is this thing doing now" items.