I had the right to not work in a union shop and to not pay dues. Government employees do not have to join the union and do not have to pay dues. Colorado is an open shop state.
As did I.
I worked for a large and rich county in Northern California for 8 years. First as a Contract worker, later as a direct employee. I did not pay one cent in union dues the entire time.
The union rep in my immediate section was a crook who did outside paid work on county time, with County equipment and supplies; years after I left he was finally discovered and fired.
When approached to pay union dues, I agreed to do so provided I chose what charity the dues would go to; the default was the Union had a list of "approved" charities, a distinction without a difference, and none of which I approved of.
The entire 5 years that I worked directly for the County was spent debating my right to name my charity of choice.
Bottom line, I had never paid a cent in "union dues," when I retired.
“Colorado is an open shop state. “
Indeed. But not Right To Work as you originally incorrectly stated.