Bigfoot, my son and I did a trip out there in 2017. I'm a spin fisherman so I don't know my flies very well, but my son is a fly fisherman.
He got a ton of useful info by just Googling, "Colorado Fishing reports." Many of the outfitters and fly shops out there post weekly updates, sometimes daily updates, and include hot patterns in their reports.
A couple of the shops I can recall off the top of my head that were good sources of info for him were Rocky Mountain Anglers in Boulder; Vail Valley Anglers in Vail; Breckenridge Outfitters in Breckenridge; and troutsflyfishing.com
There are also a few waters out there, including the Blue River, where mysis shrimp are one of the primary food sources and on those waters, that is definitely a hot fly on those waters.