Color Balance RGB

December 6, 2025

The Color Calibration is the modern tool for perfect white balance and correct colors.

In the modern workflow, this module replaces the creative work of the old “White Balance” module.

  • Old “White Balance” module: Always stays on “Camera reference” (technical basis).
  • Color Calibration: Here you set how warm or cool the image should look (creative part).

Why the switch? This module uses a technique called CAT (Chromatic Adaptation Transform). Simply put: It calculates colors as the human eye perceives them under different lighting. This leads to more natural skin tones and prevents strange color shifts in very bright areas.

The most important tabs & functions

1. “CAT” Tab (Chromatic Adaptation)

You will spend 99% of your time here. This is your new white balance.

  • Illuminant: Here you can choose presets (e.g., “Daylight”, “Shadow”, “Incandescent”).
    • Tip: “As Shot” uses your camera’s setting.
  • Picker (Color from area): The most important tool!
    1. Click on the dropper icon.
    2. Draw a rectangle in the image over an area that should actually be neutral gray or white (e.g., a gray wall, a white t-shirt).
    3. The module automatically removes the color cast.

2. “R” / “G” / “B” Tabs (Channel Mixer)

This is for advanced users. Here you can define how the camera colors (Red, Green, Blue) are mixed.

  • Application: Often used for black and white conversions (there is a “B/W Film” preset for this) or to correct extreme color casts from cheap LED lights that normal white balance cannot handle.

3. “Brightness” Tab

Allows brightness correction during color adaptation. Usually, it is better to do this in the Exposure module, but sometimes it helps here to see if a color cast is only in the shadows.

4. “Colorfulness” Tab

Here you can control brightness and saturation based on color channels. This is one of the best tools in Darktable for high-quality black and white conversions.

5. “Gray” Tab

This tab serves to computationally find a neutral gray balance based on the current channel mixer settings.

Workflow Tip: When colors look “weird”

Sometimes colors look strange after activating this module. This is often because the old “White Balance” module is not set to “Camera reference”.
Checklist:

  1. Check “White Balance” module: Is it set to “Camera reference”?
  2. Activate “Color Calibration” module.
  3. Click on a neutral area with the dropper in the “CAT” tab.

Special Case: Artificial Light

With difficult artificial light (street lamps, cheap LEDs), normal white balances often fail. Color Calibration has a “superpower” here:

  • It can compress the gamut (color space). This prevents e.g. blue LED light from becoming an unnatural, flat mush. (Found under advanced settings, if needed).

Summary

  • Use this module instead of the white balance slider in the old module.
  • The CAT tab is your main tool.
  • Use the Picker on neutral areas for quick results.

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