If your rig is like mine, there is a sheet on a cabinet door or wall that tells you the cargo carrying capacity, towing capacity, and such. Each rig's net carrying capacity is different depending on the accessories, etc. Towing for standard class C is 3,500 pounds or 5,000 in almost all cases. Yours will state what it is on the sticker/sheet. If 3,500 is the limit, you will likely need a lighter rig than the Colorado. Rule of thumb I've been told is to ideally tow a rig that is no more than 80% of the tow rating. (Not required but ideal).
This simple site may also be helpful. http://www.onlinetowingguide.com/guidelines/gvwr.html
In my case, I tow a 2003 Chevy Tracker with a curb weight of 2,987 and the RV is approved for 3,500 towing from the manufacturer. Thus, I am slightly over what I consider ideal tow weight (85%) but I reason that my Class C also has 3,000 lbs of net cargo carrying capacity and I have over 2,000 to spare when fully loaded and weighed on a local truck scale.
State laws vary, but it is always good to have a supplemental braking system for the rig you tow. I do; purchased for much less off of Craigslist, but I did buy the tow bar new (Roadmaster Falcon all terrain) and the tow brackets locally.