Color temperature

Color temperature is a scale, measured in kelvins, that describes whether a light source looks warm and yellowish or cool and bluish white. Lower numbers, roughly 2700 to 3000K, look warm and amber, similar to an incandescent bulb, while higher numbers, roughly 5000 to 6500K, look cool and closer to daylight.

Desk lamps and monitor light bars marketed for home offices often list an adjustable color temperature range, letting the light shift from a warmer tone for evening or relaxed work to a cooler, whiter tone that some people find more alerting for focused daytime tasks. Matching the desk light to the room's other lighting also helps avoid an odd mismatch of tones side by side.

There is no single correct color temperature for every desk, since preference varies by task, time of day, and personal comfort, but consistency between the monitor's white balance and the room's ambient light tends to reduce eye strain compared with a strong mismatch, such as a very warm lamp next to a very cool-toned screen.