There isn't any one definitive place to access information about converting a lawn to a meadow for Colorado. However, we can cobble together some information that might help you.

First you need to remove the turf. CSU has a fact sheet on how to renovate the lawn. Because you want to create a meadow rather than renovate your existing lawn follow the steps to get rid of your existing lawn. Here is a link to the fact sheet: https://extension.colostate.edu/topic-areas/yard-garden/renovating-the-home-lawn-7-241/

The desire to plant flowers is strong, however stable meadows are composed of 50 to 70% grasses. CSU has a list of native grasses and plants to help you make your decision. Here is a link to the lists: https://cmg.extension.colostate.edu/Gardennotes/581.pdf

https://extension.colostate.edu/topic-areas/yard-garden/native-herbaceous-perennials-for-colorado-landscapes-7-242/

You might also want to keep pollinators in mind when choosing you plants. Here is another CSU fact sheet on attracting native bees to your garden: https://extension.colostate.edu/topic-areas/insects/attracting-native-bees-landscape-5-615/

Keep a close eye on your meadow during the first year. Learn to distinguish the native plants from the weed species that will try to invade the meadow.

Don’t be surprised if your young meadow doesn’t flower much in the first year.  Many native meadow species do not bloom the first year. You can always scatter annual seeds in your meadow as well.

Good luck and have fun!