Hello,
We decided with the MiniMg V to give the choice of the 'skin' to the user only at the 1st installation, as if you bought a real miniMg (if you want another color, you have to buy another one..)..
Anyway it's feasible, but a bit tricky on a mac : you have to delete the invisible file named '.license', located in the root of the 'MiniMg V' directory (the best and maybe only solution is to use a console) and install the MiniMg again. Of course, you will also have to activate it again with your license number...