A brighly flashing multi-colored light in the night sky over Colorado viewed for a half hour.

I noticed a lone brightly blinking star of an unusual/changing shape in the night sky, and got my  binoculars. The "star" was pulsing sharp bright flashes of red, blue, and green, and multiple colors could be seen at the same time. My roommate witnessed a portion of this phenomenon also. After about 30 minutes it began flashing mostly red. I had put my phone down and turned my back for about 10 seconds to get the phone to take one more video, and when I looked again it was gone.