Back in the day, when you could still have custom icons in the sidebar of the Finder and file dialogs (well, Snow Leopard…), I used colored spheres as identifie

Back in the day, when you could still have custom icons in the sidebar of the Finder and file dialogs (well, Snow Leopard…), I used colored spheres as identifiers for project folders, for minimal 1-bit attention. Which may be a proper use case for such a thing. (There's a clear relationship, but this is also subject to change.)