I was observing what I thought was a typical satellite flare. It was moving west to east so it was not an iridium. It flared a beautiful white, maybe -9 then as soon as it diminished it flared again but stop sign red in color, maybe -4, then white, red and white after which it blinked out. Each flare lasted approx. 2-3 seconds and there was no downtime between the flares. I've never seen one flare more than once and I can't think of a explanation for the red flare. Sky was completely clear, low humidity, no moon or light pollution. Help!!
Satellite flares are sunlight reflected from a flat surface on a satellite, so it would be very unusual for one to be red at all, let alone to switch colors back and forth. It's most likely that you saw an airplane.
There are apps for mobile devices (e.g. Sky Guide for iOS) which can show you where to look for visible satellite passes, including the striking Iridium satellite flares. Checking one of those for current bright passes will quickly allow you to confirm or rule out any given phenomenon you see as a sat flare.