Large glowing phenomena emitting many colors

This was a large glowing phenomena with many colors radiating from it such as red, green, blue, like a rainbow's colors but in a large glowing area in and above the trees. Its colors shot out, and it gradually grew smaller in size so that it was beneath the trees' level. Observer was standing in bathroom shaving when he looked out at this object or phenomena, and  almost thought of getting in his car to see it closer, but it gradually grew smaller and  then seemed to just disappear.
Date is approximate.  PD