Nikon Z 6II Reference Manual page 313

3
Save changes.
•
Press J to save changes and exit to the menus.
•
If a value other than 0 is selected for
the green (G)–magenta (M) axis, an
asterisk (" U ") will appear in the icon.
D
Color-Temperature Selection
•
Do not use color-temperature selection with fluorescent light sources;
instead, use the I [Fluorescent] option.
•
When using color-temperature selection with other light sources, take a
test shot to determine if the selected value is appropriate.
C The Photo Shooting Menu: Shooting Options
271