Nikon D780 DSLR Camera (Body Only) - Manual (Page 252)

206 Shooting Settings
D Choose Color Temperature
Note that the desired results will not be obtained with flash or fluorescent
lighting. Choose
c ([ Flash ]) or I ([ Fluorescent ]) for these sources. With
other light sources, take a test shot to determine if the selected value is
appropriate.
A Color Temperature
The perceived color of a light source varies with the viewer and other
conditions. Color temperature is an objective measure of the color of a
light source, defined with reference to the temperature to which an
object would have to be heated to radiate light in the same wavelengths.
While light sources with a color temperature in the neighborhood of
5000–5500 K appear white, light sources with a lower color temperature,
such as incandescent light bulbs, appear slightly yellow or red (
q ). Light
sources with a higher color temperature appear tinged with blue ( w ).
In general, choose lower values if your pictures have a red cast or to
intentionally make colors colder, higher values if your pictures are tinged
blue or to intentionally make colors warmer.
3000 4000 5000 6000 8000 10000 [ K ]