When I want to change anything (Branch, Commit,...) on my git submodules, I usually double click on the submodule in SourceTree. Then a new Tab opens with the submodule repo. The problem is, that you can not see, that the new tab is the submodule and not any other repository.

Ideas:

1. Color the main repository and the submodule tab in a different color than the other opened tabs so the connection is clear.
2. Show a "Superproject Pointer" in the submodule view like eg Tortoise Git is doing it