Two international chains have recently opened hotels in Colón [1]. There are also two okay local places. Be prepared to be rather isolated, as it is not safe to wander far outside the hotels in and around Colón, and there’s nothing much around the more safer but more remote spots.
Again, it’s generally a better idea to make the Pacific side your base and just make day trips around here.
Links:
[1] http://www.moon.com/destinations/panama/panama-canal/colon