Canon EOS 7D Mark II Basic Instruction Manual page 57

The explanation of menu functions hereinafter assumes that you have
pressed the <M> button to display the menu screen.
You can also use <9> to operate and set menu functions. (Except for
[31: Erase images] and [51: Format card].)
To cancel the operation, press the <M> button.
Dimmed Menu Items
Example: When Multi Shot
Noise Reduction is set
Some dimmed menu items will not show the overriding function.
With [54: Clear all camera settings], you can reset the menu functions to
the default settings (p.61).
Dimmed menu items cannot be set. The
menu item is dimmed if another function
setting is overriding it.
You can see the overriding function by
selecting the dimmed menu item and
pressing <0>.
If you cancel the overriding function's
setting, the dimmed menu item will
become settable.
3 Menu Operations
57