While myself and one other person were walking through apartment complex I looked up at sky nearly vertical and saw a silver disc with six reddish-orange lights arranged evenly around bottom of disc. Disc was traveling approx 300-400mph at about 12-15,000 feet over downtown Redding heading in a straight West/Northwest direction. Lights slowly pulsated in no particular sequence fading slightly then brightening again. As the disc traveled from 80 degrees above horizon to 50 degrees it seemed to change in appearance from a reflective silver surface to an opalescent/translucent color revealing a very light pinkish-red orb at it's center. At this point alerted person with me who looked up at sky and caught a glimpse of it in this configuration. Appearance of the disc at this angle seemed to indicate some sort of camouflage or optical disturbance that seems to bend to fit the shape of the disc. Despite the actual disc becoming translucent the lights around it's circumference remained as described above- pulsating. Total time of this encounter was above 20-25 seconds until the object disappeared above cloud cover. About 20 seconds after the object passed over a small Cessna from the local airport was witnessed traveling much more slowly in about the same direction a few thousand feet below where the object was previously. The disc was about 2-3 times the diameter of the Cessna when taking into account the difference in altitude.