Silent bright craft releases smaller craft in 1976.

Observed bright white light hovering about 50 feet and 200 yards behind house. White light shone through glass doors after dark with bright light on inside.  Went outside and observed what appeared to be 2 lights come out of each side, which may possibly be rotating triangular craft but no shape was discernible.  bject made zero noise and surrounding country was very quiet.  Light that came out of left was green and the one on the right was blue.  Witness light colors vary from memory errors.  A smaller, red light appeared to come out of the light on the right and continued moving away slowly until it disappeared.  Then first two side lights went back into bright, white, center light and craft slowly moved over hill away from house and disappeared from view.  Entire event lasted approximately 10 minutes.
Witness indicates that the date of the sighting is approximate.  PD