Flashing lights moving across sky in northern direction.My friend, my neighbor, and I were sitting out on a trampoline and we were looking into the sky and saw multiple lights moving slowly across the sky (about the size of a small star). We knew it couldn't be a star because stars dont move and it couldn't be a shooting star cause it was moving very slowly. We observed that there were aircraft in the sky taking off from a local airport and we noticed that one of the objects began to follow the aircraft and then disappeared. The objects changed colors very rapidly from blue to red to white. We observed that one of the objects had a green color change in it that none of the others had. They all were moving in a northern/northeastern direction. We saw 7 or more of these objects.