Small fix for Color coding Mac MAIL folders
Like many I too would like to add color to certain folders in my Apple email app on my iMac. After searching it seems there isn't an Apple installed way, as by clinking on format, then color, the choice is grey out.
I found a very small work around that lets you add an emoji to the folder.
Once the mailbox is created and a name is added, go back to the name and click on the name as if you are going to correct the spelling or use a different name. Once the name is highlighted go up top to the Apple main menu and click on Edit. Move all the way to the bottom and select "Emoji and Symbols". You then can assign a Emoji or Symbol can can represent the folder... a Doctor..etc. I find it better than nothing.
Warren
iMac 21.5″, macOS 10.13