Sadly, forums seem to be on the severe decline and ones for Colorado are in short supply. This site (http://www.coloradofisherman.com/) seems to be okay, but is not 100% fly fishing focused though it is active enough for a narrowly focused site. My guess would be someone there can answer your question. My personal recommendation would be to check with your local (or nearby) shops. I would say talk to shops in Colorado Springs or Denver (my recommendation for Denver area would be Charlie's Fly Box in Arvada), and see what they recommend for Colorado brook trout.
"My father was very sure about certain matters pertaining to the universe. To him, all good things - trout as well as eternal salvation - come by grace and grace comes by art and art does not come easy." Norman Maclean, A River Runs Through It