Object moved very slowly with flashes/beams of light irregular in frequency emitting from it.

At approximately 21:15 pm central standard time in Columbia, MO, my spouse and I were on our back deck looking towards the south while smoking.  I noticed a strange flash of white light towards the southwest part of the sky and began watching for it again.  It flashed again around 10 seconds later but flashed in an irregular way now in a blue and red beam of movement like a very slow motion trail.  It continued to flash mostly either faint or extremely bright flashes of white light with no pattern or rhythm of flashing, and once in a blue moon it had the flash of blue and red again similar to a meteorite breaking up in the atmosphere but in a more controlled way.  It inched slowly across the sky from west to east in a horizontal direction until disappearing behind the trees.
It moved much too slow to be an airplane, satellite, or the ISS.  It was clearly in the sky and not out in space, and guessing roughly it was probably 5-10,000 feet off the ground; perhaps a 1/2 a mile to a mile from our location.  In about 15-20 minutes it had moved so slowly that it only covered about 10 feet of the sky from our point of view.  Any passenger or military plane or helicopters I've seen here would cover that distance in under 20 seconds.  The B-2s fly out here quite often too with Whiteman AFB being so close.  Definitely wasn't that and didn't sound like the B-2.  This object had no sound whatsoever.
Witness elects to remain totally anonymous; provides no contact information.  PD