I have MM-15, but I've never seen any way to control the colors of the arranger itself. If you are a programmer, you might be able to hack the program but that is against the user's agreement.
You CAN adjust the colors of objects in the arranger.
Go to... (Object Menu) > Advanced properties > Properties... (CTRL+E)
In the object block, choose Foreground Color or Background Color.
I have MM-15, but I've never seen any way to control the colors of the arranger itself. If you are a programmer, you might be able to hack the program, but that is against the user's agreement.
You CAN adjust the colors of objects in the arranger.
Go to... (Object Menu) > Advanced properties > Properties... (CTRL+E)
In the object block, choose Foreground Color or Background Color.