Color changing lights slowly approaching

At approximately 9:21 p.m. my girlfriend and myself went to take out the garbage. The sun was set but it was still a little daylight. She noticed what she thought was a bright colorful star. After watching it for a while she went inside and I continued to watch. As I watched I realized that this object was a lot smaller than what it appeared to be the closer it came the dimmer the light got. Out of my peripheral I noticed another smaller object to this objects left approaching in the same manner. Then there was a larger one that displayed the most beautiful brightest colors that never left it's location in the sky. It kind of just bobbed around up there. The others slowly in a floating manner proceeded to the water tower. In about an hour there was at least 5 orb like objects hovering over and around the water tower. They were mostly silent other than random high-pitched yips here and there. The neighboring dogs were going crazy barking at them.Their lights would dim out at approaching vehicles. They looked to be analyzing/ searching the water tower. They have been back The past 3 nights same time same location.