Maybe i missed it somewhere or it's not a feature, but here i am again, colors per category (and maybe also the columns) like we discussed before. Kanban without colors doesn't exist. 
And an answere to your answere somewhere above: Sorry, i know TypeScript is becoming a nice programming language but no experience in that.
Colors mostly used for columns:
- Backlog: Yellow
- Progress: Green
- Done: Blue
- Archive: Black
_ Example: https://ps.w.org/kanban/assets/screenshot-1.png?rev=1435103
Colors that can be used for categories:
- Orange
- Brown
- Purple
- ...
_ Example: https://kanboard.org/
_ In Nextcloud Deck webapp and mobile app it looks like this:
https://apps.nextcloud.com/apps/deck
Thanks for this nice and long-awaited plugin!
Some rapid mockups how it could look:
