Today on a United Express operated by Skywest flight, the CRJ was in Skywest colors, not United Express. It looked similar to this one:
http://www.airteamimages.com/pages/skywest/skywest.html
I have flown on many Skywest EMB120's that have Skywest Painted on them and are not done up in United colors but this was the first CRJ. I asked the flight attendant and she said that the plane had started its day flying Delta segments and upon arriving at ORD had switched to doing United Express runs for the rest of the day.