if users have several apps for several purposes, it would help them to work in the right context. As for now, it is not all too obvious, to find out for the user herself that she's working in the wrong model driven app and, therefore, unable to see or do some of the tasks. If only we could change the color, it would easier for the user (and admins) to spot when they are working in the wrong app (sometimes one user sends a link containing an appid which opens the record in the wrong app for the destination user) and this one gets stuck with something weird to her.