Kelvin to RGB Converter

How Kelvin converts to RGB

There is no single exact answer — a colour temperature describes the spectrum of a blackbody radiator, and turning that spectrum into three screen primaries requires an approximation. The converter above uses Tanner Helland's blackbody approximation, accurate across roughly 1,000K to 40,000K, which is the same maths the slider and Luttie's white balance control use. Mired (micro reciprocal degrees) is simply 1,000,000 divided by the Kelvin value; filters and gels are rated in mired shift because equal mired steps look like equal colour changes to the eye, while equal Kelvin steps do not.

What is color temperature?

Color temperature describes the color of light emitted by a theoretical blackbody radiator at a given temperature, measured in Kelvin (K). Lower values (1800–3500K) are warm and orange; higher values (6000K+) are cool and blue. Despite the naming, “warm” light has a lower Kelvin value and “cool” light has a higher one — which is the reverse of what most people expect.

How color temperature affects your grade

White balance is the starting point for any color grade. When your camera records footage in mixed lighting — part tungsten, part daylight — the auto white balance often settles on a compromise that satisfies neither. Setting white balance manually, or correcting it in post before grading, means your creative grade starts from a neutral base rather than fighting the color cast.

In RAW files, white balance is just metadata. Changing it in post is mathematically lossless. In JPEGs, it's already baked in, so you're working with degraded data. This is one of the core reasons to shoot RAW.

Common Kelvin values for photographers