I'm not sure if you've answered this question before, but do you accept community contributions to your repo/project? I noticed the code on github you posted is from April of last year even though you've pushed updates the past month. I want to add a specific feature to change the colors of districts more than what is available from the current toggles. 

https://itch.io/t/485502/source-code

If you want to implement a specific feature for yourself you can download the project (i.e. its compiled JS version) and make the changes you need. It's not too convenient but doable.