C'mon OP. On this board, given sufficient time, every single colour available will be recommended. Maybe even some not available
It's a personal choice and subjective. So much so that what catches one person's eye will not catch another. I'm partial to blue, but others hate it.
If you want to be noticed, perhaps the M5 is not really the car for you. While we on these forums appreciate it, most people in the general public won't even give a BMW sedan a second look. I recommend buying the car and colour for you. It's a lot of money and should make you happy.