pulsing blue light with irratic movement

I saw an indigo blue light that was pulsing. I saw One green light, and one regular incandescent light. 
It did not move in the form of a plane or a helicopter. It was twirling and tumbling on it's axis. It appeared to be "triad" in architecture. 
It would move from left to right, in & out, light intensity varying. It dipped below, from my point of view below tree line, once, it reappeared in a diagonal rising fashion, then dipped below once gain not to be seen again.