so red and green in aviation has meaning.
so maybe what you saw was drone heading toward you, then sstopped and rotated 180 degrees and now you see red. Then another 180 and green again.
You can buy drones with, or as an accessory.
I would imagine that someone out there im sure has fitted theirs with god knows how many LEDs ( think neon in wheel wells of trucks )
Shoot i saw a lifted Escalade two weeks ago that had leds around the hub/spindle- all 4. couldnt even make out the tires they were so bright.