Use a Column in Data Set to Assign Colors to Cities for Visualizations.

I've tried several different ways to achieve this and have been unsuccessful.  Is there a way to use a color column on my data set to assign HEX colors to cities?  Most of the conditional formatting videos and articles on the web I have found are just a small list of brands to use SWITCH to assign colors, but my list is too long for that measure method.  I'm not sure if I can so this with a custom theme using JSON.  I don't think it allows me to get that granular in the coloring.  Ultimately, I want all the cities to have the same colors in all my visualizations.  See the two columns in my data set with the cities and HEX colors.

Thank you!

CC