Colorado seems like the type of state that can't really gain a "reputation," politically or otherwise, because it changes so much. Colorado 1990 is NOTHING like Colorado 2000, which is nothing like Colorado 2018. It's a constantly changing state, it seems.
That may be true, but the state is also extremely varied. Whilst it is the big cities that give Colorado the Democratic vote, it also has a concentration of rural Democratic resort counties otherwise occurring only in the area comprising southern Vermont, western Massachusetts and Cheshire and Grafton Counties of New Hampshire.
Even the Republican-trending Hispanic counties of Southern Colorado are varied in themselves. Las Animas County showed a trend analogous to Appalachia or the Midwest, yet relatively nearby Alamosa County voted for a losing Democrat for the first time since it was created in 1916. In the case of Pueblo and Las Animas there may also be increasing influences from the arch-Republican High Plains upon the culture and politics.
Colorado's inelasticity and high level of polarization are explained by its sheer
diversity, which you've laid out well in your post. It has a solidly Democratic, diverse, and highly urbanized city in Denver, sort of a mini-Chicago or a mini-Los Angeles. It has a solidly Democratic and very liberal college town in Boulder (Boulder County)-Colorado's version of Charlottesville or Berkeley. It has a Democratic-leaning college town in Fort Collins (Larimer County)-the equivalent of Blacksburg, Virginia, or Columbia, Missouri. Greeley (Weld County) is Colorado's version of Midland County, Texas or Tulsa County, Oklahoma. Douglas County, Colorado is our version of Hamilton County, Indiana or Williamson County, Tennessee.
El Paso County, Colorado is akin to Bexar County, Texas (minus the heavy Hispanic influence), Oklahoma County, Oklahoma (solidly Republican city), or Bell County, Texas (heavy military presence). The Eastern Plains are an extension of Kansas or Nebraska, the ski counties parallel the liberal rural counties of New England, and Pueblo County, along with adjacent Las Animas, Huerfano, and Conejos Counties, are sort of a mini Rust Belt. And the suburbs of Denver-Adams, Arapahoe, Broomfield, and Jefferson Counties-are akin to the Collar Counties of Philadelphia or the Collar Counties of Chicago. Colorado also has it's "Wild West" type rural areas, found in western and Central Colorado, and the Hispanic counties parallel those found in Arizona, New Mexico, or Texas.
I've always been amazed by how Denver and Colorado Springs are located in the same state, when there is so much that is different between them.