In order to sell any type of food product in Colorado, it must be produced in a licensed facility. Licensing is generally done under state regulations as interpreted and enforced by county health departments.
There is one exception to this - the 2012 Cottage Food Act. You can find information about this here. You can download the full Cottage Food Actby clicking this link.
To begin exploring the licensing process, learn about the licensing requirements and procedures in the county where your facility is (or will be) located).
Note that there is no such thing as "a licensed kitchen" -- a license is required by each business operating in a facility. So if you arrange to share kitchen time with someone already running a business, you will need to go through the licensing process yourself, for your business, in the facility in which you will operate.
You can find lots more information about licensing and regulatory matter at the excellent web site Colorado Farm to Market
These days, Food Trucks have become very popular. Here is a web site put together by an attorney which has lots of information about food trucks and related matters. Good info for others too - Check it out! How to Start a Food Truck Business in Colorado
Here are some documents you should review if you are planning to start a food business: