Having flown the RJ - IAH to PSP several times - in the beginning you would hear comments from surprised passengers as they boarded.
CO needs to code share with NW and DL on the PSP route and offer it on co.com. NW code shares with CO on the RJ route through IAH - but CO does not do the opposite.
I also heard that CO was going to code share with another PSP carrier - to route passengers to another city in CA. CO used to code share with AA Eagle on the LAX-PSP route - but I do not think AA Eagle flies this route anymore.