Highlight specific categories with a background color

I think it would be helpful if there was an option to highlight specific categories within a board by changing the background color of the category (see below). 

For my personal task board, I have categories for rush requests and clarifications.  I'd find it helpful if these categories popped out at me.  I currently put tags on each task but this looks a little busy.  It also feels redundant to me when I put a tag called "Clarification" on a task I've put in the "Clarification" category.

For team boards, it could be helpful to color coordinate categories by department/project.  And/or any new categories could be assigned a color so they pop out to the team members.

Here's a quick mock-up of what I'm picturing:

Thanks!

-Lauren