Color Temperature to RGB Converter (Kelvin)
Convert a color temperature in Kelvin (1000–12000K) to an approximate sRGB color and hex, with common light-source references. Runs in your browser.
Lower temperatures look warm (orange/red), higher look cool (blue) — the opposite of the everyday “warm/cool” intuition. This uses the widely cited Tanner Helland approximation of black-body color, accurate to a few RGB levels across roughly 1000–40000 K; it is an approximation of perceived screen color, not a colorimetric (CIE) conversion. Everything runs in your browser.
About this tool
Color temperature describes the color of light emitted by an idealized 'black body' radiator heated to a given temperature, measured in kelvin (K). It is the scale photographers, videographers, lighting designers, and display engineers use to characterize the warmth or coolness of a light source or white point. Counterintuitively, lower temperatures produce warm, orange-red light (a candle is about 1900K, a household incandescent bulb about 2700K) while higher temperatures produce cool, bluish light (overcast daylight is around 6500–7500K, deep blue sky shade can exceed 10000K) — the reverse of the everyday sense of 'warm' and 'cool.' This converter turns a kelvin value into the approximate red, green, and blue values you would use to represent that light on a screen, shown as a live swatch plus hex and rgb() codes. It uses the well-known Tanner Helland approximation, a set of curve-fitted formulas that reproduce black-body color to within a few RGB levels across roughly 1000K to 40000K — accurate enough for UI swatches, white-balance previews, and lighting mockups. It is important to understand what this is and is not: it approximates the perceived on-screen color of black-body light, not a rigorous colorimetric conversion through the CIE color spaces, and it does not account for your display's gamut or calibration. For design and reference work it is plenty; for color-critical pipeline work you would use a full CIE-based transform. The reference buttons let you jump to common sources — candlelight, tungsten, daylight (D50/D65), flash, overcast — to see how each maps to RGB. Everything runs in your browser; nothing is uploaded.
How to use it
- Drag the slider or type a color temperature in kelvin (1000–12000K typical).
- Read the resulting sRGB swatch, hex code, and rgb() values.
- Click a light-source reference (candle, daylight, etc.) to jump to its temperature.
- Copy the hex/rgb for use in your design or lighting setup.
Frequently asked questions
- Why does lower Kelvin look warmer (more orange)?
- Color temperature follows black-body physics: a cooler black body glows red/orange, a hotter one glows blue-white. So low kelvin = warm light, high kelvin = cool light — the opposite of the casual use of "warm" and "cool."
- How accurate is this conversion?
- It uses the Tanner Helland approximation, accurate to within a few RGB levels from about 1000K to 40000K. It is excellent for swatches and previews but is an approximation of perceived screen color, not a colorimetric CIE conversion.
- What are common color temperatures?
- Candle ~1900K, incandescent ~2700K, studio tungsten ~3200K, horizon daylight (D50) ~5000K, midday sun/flash ~5500K, daylight (D65) ~6500K, overcast ~7500K, blue shade ~10000K.
- What is the difference from a CIE conversion?
- A full conversion maps black-body temperature to CIE chromaticity then to your display's gamut with proper white-point handling. This tool skips that for a fast RGB estimate — fine for design, not for color-managed production pipelines.
- What is D50 vs D65?
- Standard daylight illuminants: D50 (~5000K) is the print/graphic-arts reference, D65 (~6500K) is the standard for displays and sRGB. They define a "white" reference for color work.
- Is anything uploaded?
- No. The conversion runs entirely in your browser.