2016's rate was a 12-year high, but still remained well below the homicide rates that were common during the 1970s and 1980s:
Compared to the nationwide homicide rate, the Colorado rate has been lower every year since 1963. The nationwide homicide rate in 2016 was 5.2 per 100,000.
Compared to other US states and Canadian provinces, Colorado's homicide rate places it as one of the lowest-homicide rates in in the US, and puts it on a par with central-Canadian provinces like Alberta and Manitoba:
As a map:
Within the state of Colorado, metro areas can differ significantly. Over the past decade, the metro area with the highest homicide rate has in most years been Pueblo (no Pueblo data is available for 2008). In 2016, Colorado metro areas reported the following homicide rates, per 100,000:
Grand Junction: 6
Colorado Springs: 4.5
Fort Collins: 2.6
By this measure, Fort Collins and Greeley are among the safest places in the world. Grand Junction's homicide rate spiked in 2016, but with such a small overall population, it's impossible to say if this change reflects any real trend in the region.
These numbers, however, are by full metro areas. If we look within a single metro area, such as the Denver Metro Area, we'll find significant differences there as well. For example, the City and County of Denver is the primary driver of homicide rates in the area. In 2016, there were 57 homicides in the City and County of Denver, and 22 in the City of Aurora. In the metro area as a whole, however, there were 124 homicides total. Thus, Denver and Aurora alone accounted for nearly two-thirds (63 percent) of all homicides in the metro area. This is in spite of the fact that those two cities make up only 37 percent of the total population of the metro area.