Surfing around www.flightaware.com tonite, I saw a CO9970 arriving at IAH. It's a 753 flew in from Greenville, MS (GLH). Googling that airport, I found that Aviation Exteriors is located there, a major paint shop. So, looks like there should be a newly painted 753 at IAH joining the fleet soon.

And while checking out that flight number 9970, it's also often used for 738 ferry flights to Abbostford, British Columbia (YXX). Found out that CO is a customer of the maintenance company Cascade Aerospace.

Learn something new every day.