It can be difficult to find reliable info on fire restrictions in Colorado. Sometimes the forest service will have restrictions on a particular area, but more frequently, individual counties will have fire restrictions. The county websites are usually better posted and organized than the USFS websites. On either, typically I would assume no info = no fire ban, but that may not always be true.
I wish there was a good map to clearly show all fire restrictions. This one gathers all the county info, but leaves out much of the USFS info, and doesn’t inspire confidence that anything is actually up to date: http://www.coemergency.com/p/fire-bans-danger.html
“No fires at XXX Lake” typically means no fires anywhere near the lake, or even in the basin the lake is in. On the way to a particular lake in Indian Peaks Wilderness, I passed a sign on the trail that said no fires within 1/2 mile of the lake. Lakes are heavily used camp areas, and often in high alpine areas with short tree growth seasons, and in addition to preventing wildfires, they are trying to avoid all the wood fuel from disappearing faster than it can recover, including both dead/down wood and still living wood (from irresponsible fuel gathering).
When fires are legal in an area, I would suggest using your common sense in your decision to have a fire, based conditions around you. Lots of dead/dormant/brown vegetation around your campsite, likely a bad idea. Lots of lush green vegetation around, probably fine to have a small controlled camp fire. Have a source of water nearby to truly put the fire out. I use my gravity filter water bag to dump several gallons on the hot coals.
I’ve been backpacking with kids in Colorado for the last several years, feel free to PM me with specific questions. Lakes are often busy too, I suggest a meadow area with a nice stream for fishing.