Canon EOS-1D X Mark II DSLR Camera (Body Only) - Manual (Page 185)

185
You can set the white balance’s color temperature numerically. This
function is for advanced users.
1
Press the < B > button ( 9 ) .
2
Select < P >.
Look at the top LCD panel and turn
the <
5 > dial to select < P >.
3
Set the color temperature.
Turn the < 6 > dial to set the color
temperature.
The color temperature can be set
from approx. 2500 K to 10000 K in
100 K increments.
P
Setting the Color Temperature
When setting the color temperature for an artificial light source, set white
balance correction (magenta or green) as necessary.
If you set < P > to the reading taken with a commercially-available color
temperature meter, take test shots and adjust the setting to compensate
for the difference between the color temperature meter’s reading and the
camera’s color temperature reading.
You can also set this with the [ z 1: White balance ] screen.