Shifting lights around disk with dome.

On several nights in late August and early September myself and several neighbors observed a craft near our homes. The vehicle hovered silently. It's shape was that of a disk with a dome in the middle. Along the disk length was a row of white lights, while the center dome shifted between red, green, and blue light. Comparing the sighting with sky charts proved it was not any known celestial object; it was in the area of the constellation of Bootes on our northwest horizon. My neighbor noted that, on the night of September the first, it was hovering in the west, and quickly zipped to the northwest, near Seginus, around the time I came outside. It remained hovering and color shifting while I recorded it. Since Bootes moved beyond our horizon, I have not spotted it again.