Strange icon after upgrading room?

[Vorshin]

I just upgraded my cafeteria (3 slot room and 2 upgrades) but were the upgrade icon is i have what looks like a paintbrush icon? Whats this, as far as i can tell it does nothing, I have upgarded power, water and other cafe's without this icon appearing, is it a bug?

[Ryuu]

Themes. Wait till you make Theme Workshop.

[greeb]

lol, i also have my diner on cafe