The GUI for invoking a change in the current Camera set should be as small and unobtrusive as possible. In thinking about how to do that I believe the best answer is to rely on a toggle effect where some visual change occurs to signify the current state after being clicked upon. That gives a much smaller GUI than if OFF and ON text was present. With that in mind, a simple list would suffice and allowing for the GUI to be presented in either horizontal or vertical orientation should allow each use to have the display set per their own tastes. Examples:

The above shows the list when Roles are defined. As you can see in either orientation there is one that looks different than the others... that's the current state.
Alternatively, this one:

could be used when no roles are desired and the player just wants to take advantage of camera sets.
As I see it the difference between the two is Roles can have a command Gui; perhaps the distinction isn't actually necessary tho... a matter for further thought.
WRT color, whatever looks right. For instance, a dark background using Yellow letters to signify the current state:
