Image Color Temperature Adjuster
Warm or cool any photo by Kelvin value, from 1000 K candlelight to 40000 K deep shade, with a green-magenta tint slider and a preserve-luminance option.
Blackbody colour at this temperature
6600 K is the neutral point — below it the photo warms toward amber, above it it cools toward blue.
What is the Image Color Temperature Adjuster?
Warming or cooling a photo means multiplying its channels by the colour a blackbody radiator emits at a given temperature.
- Kelvin slider from 1000 K to 12000 K plus an exact input up to 40000 K
- Blackbody colour swatch with a plain-English lighting description
- Green and magenta tint slider for the second colour axis
- Preserve-luminance option so brightness does not drift
- Live channel multipliers shown for the current settings
- Runs 100% in your browser and exports a full-resolution PNG
How to use the Image Color Temperature Adjuster
- 1
Drop a photo into the upload area to warm or cool it.
- 2
Drag the colour temperature slider, or type an exact Kelvin value in the box below it.
- 3
Nudge the tint slider toward green or magenta to correct a secondary cast.
- 4
Leave Preserve luminance ticked to keep the original brightness, or untick it for the raw multiplication.
- 5
Click Download PNG to export the adjusted image at full resolution.
About the Image Color Temperature Adjuster
Warming or cooling a photo means multiplying its channels by the colour a blackbody radiator emits at a given temperature. ByteTools converts any Kelvin value from 1000 K to 40000 K into red, green and blue multipliers using Tanner Helland's well-known approximation, then applies them to your image. 6600 K is the neutral point: below it the picture warms toward amber, above it it cools toward blue.
Temperature alone cannot fix every cast, so there is a second slider for the green and magenta tint axis that photo editors always pair with it. Preserve luminance keeps the overall brightness where it was while the hue shifts, and a live swatch shows the blackbody colour along with the exact channel multipliers for the temperature you picked.
Pixels are transformed on an HTML canvas inside your browser, which makes the whole thing 100% local — nothing is uploaded to a server and private photos stay on your device. The preview updates as you drag the slider, and the download is rendered at the original resolution as a PNG.
Frequently asked questions
What does colour temperature mean in photography?
Colour temperature describes the hue of a light source in Kelvin, based on the colour a theoretical blackbody glows at that temperature. Low values around 2000 K are warm and orange like candlelight, while high values above 7000 K are cool and blue like open shade.
How do I make a photo look warmer?
Drag the temperature slider below the 6600 K neutral point, toward roughly 3000 K to 4500 K for a natural golden-hour feel. The lower you go the more amber the image becomes, and the preview updates live so you can stop where it still looks believable.
What does the tint slider do that temperature does not?
Temperature moves the image along the blue-to-amber axis only. Many light sources, especially fluorescent and LED tubes, also add a green or magenta shift that temperature cannot cancel, so the tint slider provides that second perpendicular correction.
Why should I preserve luminance?
Multiplying channels by values below 1 makes the picture darker as a side effect of the hue change. Preserve luminance measures brightness before and after and rescales the result, so you see a pure colour shift rather than a colour shift plus an exposure change.
Is this the same as white balance?
They are related but opposite in intent. White balance tries to remove the colour of the light automatically, while this tool lets you dial a temperature in deliberately, either to correct a cast by hand or to add a warm or cool mood on purpose.
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