Constructing a counter in Windows Movie Maker

I have this .mp4 video where I'm doing push-ups. At the begiing of each push-up, there is an area on the video where the color is red. When I go to the bottom, it's white, and when I push back up, it's red again, signifying I performed a push-up.

I want to make a counter and increase the count from '0' every time that the area changes from white to red. How do I do that?