Issue Summary

Deleting the users under Card Colours sort by Assignee does not work after refreshing the page.

Steps to Reproduce

1. In the board, go to Board > Configure > Card Colors
2. Configure it to Assignee
3. There are about 6 assignees in the board
   
4. I deleted Apple and Test user from the Card colors
   
5. Refresh the page

Expected Results

The users that I deleted will vanish even after refresh.

Actual Results

1. After the refresh, the two users that I deleted are back.
   

Workaround

Currently, there is no known workaround for this behaviour. A workaround will be added here when available