Set white balance

White balance decides which color in the photo counts as neutral. Set it by clicking something that should be gray or white, or by hand with two sliders.

Pick a neutral

1. Click the pipette beside Basic Color in the General section, or press W (by default). The cursor becomes an eyedropper.
2. Move over the photo. A small readout shows the color under the pointer and the temperature and tint a click would set.
3. Click a neutral spot, such as a gray card or a white wall. Or drag a rectangle to average an area, which is steadier on textured surfaces.

WB Temperature and WB Tint move to the new values. The tool stays on so you can try other spots. Press Esc to leave it. If you are dragging a rectangle, the first Esc cancels the rectangle and the second leaves the tool.

Each pick is one undo step. The picker reads the photo as the active layer’s white balance sees it, before the white balance and the edits after it, so Before / After makes no difference. A readout in the warning color says “out of range” when no setting can neutralize the spot.

Set it by hand

Drag the sliders in General › Basic Color.

Control	Range	Default	Moving it
WB Temperature	2500 to 12000 K	The photo’s as-shot value	Up warms the photo (more yellow), down cools it (more blue)
WB Tint	-150 to +150	0	Up adds magenta, down adds green

WB Temperature moves evenly in mireds, not in kelvin, so the warm end has as much track as the cool end. A Shift-drag moves in fine steps. Double-click either slider to return it to its default.

Set white balance on a layer

On a local layer, WB Temperature is an offset from the Base layer’s white. It still shows kelvin, and double-clicking it goes back to the Base white. If you change the Base white balance later, the layer follows. The picker works on whichever layer is active. See Layers.

Note

Paste Edits keeps the target photo’s as-shot white balance. See the effects pages for copying edits between photos.

Technical details: how white balance is applied

White balance is done on linear light in the working space (linear ProPhoto RGB). DarkRay finds the source white and the target white on the daylight and blackbody curve, and scales red and blue by the ratio between them. Tint scales green by at most 10 percent at ±150.

The picker undoes this math: from the average color of the sample it finds the temperature at which red equals blue, then the tint that makes green match. Values round to 1 K and 1 tint unit, so picking the same spot twice gives the same answer. A spot that needs a temperature outside 2500 to 12000 K, or a tint beyond ±150, is set to the limit and flagged.

The viewer shows a proxy a third of full size, so a click averages a small cell of the real photo.