White Balance Corrector
Remove the orange glow of indoor bulbs, the blue tint of shade or the green cast of fluorescent tubes. Click something that should be neutral gray, or let the automatic gray world or white patch method measure the cast, then fine-tune with temperature and tint.
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Gray world assumes the scene averages to neutral gray. For an exact fix, press Pick gray point and click something white, gray or black in the photo.
How to use the White Balance Corrector
- Open a photo with a color cast by dropping, pasting or choosing it. A sample shot under orange tungsten light loads first, with its gray card already picked.
- Press Pick gray point and click an area that should be neutral, such as white paper, a gray wall, concrete or a gray card. Or choose Auto: gray world or Auto: white patch.
- Fine-tune. Move Temperature toward Warmer or Cooler and Tint toward Green or Magenta until skin and whites look right. Lower Strength to keep some warmth.
- Compare by dragging across the photo or with the before/after slider, and read the detected cast and multipliers below the image.
- Download the corrected photo as JPG, PNG or WebP, or copy the RGB gains to reuse them.
Common color casts and how to fix them
| Light source | Typical color temperature | Cast in the photo | Best fix |
|---|---|---|---|
| Candle, fireplace | ≈ 1,800–2,000 K | Deep orange | Gray point, then Strength 70–85% to keep some warmth |
| Household tungsten / warm LED bulb | ≈ 2,700–3,200 K | Orange-yellow | Gray point on a white wall or paper |
| Fluorescent tube, some cheap LEDs | ≈ 4,000 K, with a green spike | Yellow-green | Gray point, then Tint a little toward Magenta if needed |
| Midday sun | ≈ 5,000–5,500 K | Neutral | Usually none needed |
| Overcast sky | ≈ 6,500–7,500 K | Slightly blue | Gray world, or Warm quick look |
| Open shade under blue sky | ≈ 8,000–10,000 K | Blue | Gray point on concrete or a white shirt |
| Underwater | Red light absorbed with depth | Blue-green | White patch or gray point on sand |
Kelvin values are approximate and vary between bulbs and weather conditions.
How the correction works
- Linearize. Pixel values are converted from sRGB to linear light with the standard sRGB transfer function, because light mixes linearly and camera white balance is applied before gamma.
- Measure the reference. For a gray point, the average of a small square around your click; for gray world, the mean of all pixels except clipped (above 250) and near-black (below 6) ones; for white patch, the mean of the brightest 1% of non-clipped pixels.
- Compute gains. Each channel gain is Y ÷ channel, where Y is the reference luminance. Multiplying by these gains turns the reference into a neutral gray of the same brightness.
- Add temperature and tint. Temperature multiplies red by e0.4t and blue by e−0.4t; tint multiplies green by e−0.3m. All gains are then divided by their combined luminance so the photo does not get brighter or darker.
- Apply the three multipliers to every pixel and convert back to sRGB.
Tips
- Carry a gray card or photograph a sheet of white paper in the same light; you can then correct every photo from that session with the same gray point.
- Do not neutralize sunsets. Golden hour and candlelight are meant to be warm. Lower Strength or skip the correction.
- Check skin tones. If faces still look too pink or green after a correction, nudge Tint by 5–10.
- Brighten afterwards with Brighten Image if the photo is also underexposed.
Frequently asked questions
What is white balance?
White balance is the adjustment that makes white and gray objects look neutral under different light. Candle and tungsten bulbs are orange (about 1,900 to 3,200 K), midday sun is near 5,500 K and blue sky shade can be 7,000 to 10,000 K. Our eyes adapt automatically, but a camera records the light's color, so photos look orange indoors or blue in the shade unless white balance is corrected.
Which method should I use: gray point, gray world or white patch?
Pick a gray point whenever the photo contains something you know is neutral; it is the most accurate. Gray world works well for busy scenes with many different colors. White patch is best when there is a white wall, paper, snow or clouds that are bright but not completely blown out. Try each and compare; it only takes a click.
What makes a good gray point?
A matte, mid-gray or light-gray area with some texture but no strong color: a photographer's gray card, white printer paper, a white T-shirt in light shade, concrete, road markings or the gray of a stone wall. Avoid pure white highlights (they are clipped and carry no color information), shiny reflections and very dark shadows, which are noisy.
How is the correction calculated?
The tool converts the reference color from sRGB to linear light, then multiplies the red, green and blue channels so the reference becomes neutral gray with the same luminance (Y = 0.2126 R + 0.7152 G + 0.0722 B). Temperature and tint are applied as extra multipliers, and the result is normalized so overall brightness stays the same. This matches the von Kries style channel scaling used in camera white balance.
Why does gray world sometimes make the photo look wrong?
Gray world assumes the average color of the scene is gray. A photo dominated by one color, like a green lawn, a blue swimming pool or a red sunset, breaks that assumption, so the method removes color that is really there. Use a gray point or lower the Strength slider in those cases.
What does the kelvin estimate mean?
It is the correlated color temperature of the reference color, computed with McCamy's formula from its CIE xy chromaticity. On a display calibrated to sRGB, neutral white is about 6,500 K; a reference near 3,000 K means the scene was lit by warm, tungsten-like light, and above 7,500 K means a cool, bluish light. Treat it as an approximation, especially for colors far from neutral.
Is my photo uploaded?
No. The photo is opened and corrected inside your browser with the Canvas API. The corrected file is created on your device and nothing is sent to a server.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.