Welcome to Retool.
I can tell you how I manage tag color. May not be applicable to you, but hopefully you can get some clues for your use case. The method does take a few more steps to set up but has the advantage of all of the colors being the same throughout all of the apps.
All of my lookup table (like status) have a color field that holds the hex value of the color I want to use:
| task_status_id | task_status | color |
|---|---|---|
| 3 | Entered | #5a81d9 |
| 4 | In Progress | #3f40bb |
| 5 | On Hold | #f50400 |
| 6 | Complete | #139118 |
My table column settings look like thjis:
My table takes those colors:
I also have a System Settings page where I can edit all of my lookup tables:
You can type in the hex code, but I use a color picker component I made so the client can easily change the colors to what they want: