"Christmas Star" - Multicolored, pulsating sphere spotted on northern horizon.While driving on a county road south west of Purcell, Oklahoma, myself and two others observed a bright, pulsating, multicolored, sphere-shaped light above the northern horizon. It appeared to be stationary and was probably 10-15 miles away from us over the Norman, Oklahoma, area.I have observed aircraft with their landing lights on coming and going from the Oklahoma City area for years, but none of them pulsated and changed colors as this light did. It seemed to flash red, white, blue, orange and possibly green in quick procession. We joked that it was a "Christmas star" because of the colors. We lost sight of it because we went down a hill. By the time we got a view of the horizon again, it was gone.I have observed many strange aircraft lights along that horizon in previous years and it seems that more and more reports of these lights are being made. I suspect it might have something to do with Tinker Air Force Base.