Custom Block Categories?

Like lets say a project has a ton of custom blocks, what if you could split them up into categories? Scratch addons I think has the ability to recolor custom blocks but what if you could create local categories for custom blocks where each category has an assigned color? Something like shown in the image. (Doesn't matter if it is only visible to the creator or visible to everyone who has the addon enabled, I think it'd be great for organizing custom blocks either way.)