My family and I went to see a local fireworks show in Fairfax. It was around 9 pm when my mom pointed out an object a little above the horizon that seemed to be stationary. It seemed to be switching from a green light to a red light continuously. It could easily have been mistaken for a plane coming towards us, however the time between its pulses was slightly longer than a plane's. We decided to watch it. It was going towards the "left" then it came to a stop and as if it knew it was spotted, it made a dip and went behind the trees in the horizon. Later last night, we saw the same object 2 more times. In all instances, it went behind something as if it knew it was being seen. Also, it seemed to go towards the fireworks when the shows started. Throughout the first round of fireworks, it was visible, and interestingly, it switched to flickering its lights from pulsating as if it was camouflaging itself. When the fireworks were not being used, it was only pulsating. The second object, or "light" we saw was a more white-cream color, and slightly bigger. It went towards the sky and we didn't see that one for a long duration.