6. The Tools in the Toolbox / 6.3 Tools for Image Layers
6.3.10 The Color Gradient 

In
the tool settings, a predefined gradient can be selected or the existing
gradient can be modified.
Properties of a Gradient
The appearance of a gradient is determined by several properties:
- The color model (under Channels).
- Different color models are available: the color model of the document
(see chapter 2.11), HIS, HSV and Lab. When calculating the gradient,
intermediate colors are calculated in the set color model. This makes e.g.
gradients in HIS and HSV more colorful than in RGB.
- The colors of the gradient
- The colors of the gradient can be changed via a control element
consisting of a gradient bar and a bar containing the colors of the
gradient.
- By clicking on the gradient bar you can select a predefined gradient. You
can predefine your own gradients in the Color Editor (see chapter 3.4) or
by dragging a gradient into the Gradient List (see chapter 4.14).
- The color fields below the gradient bar can be moved with the mouse. If
you drag a color field down or up out of the color bar, it will be deleted.
If you click into the free area, a new color field will be created. The
color of the color fields can be changed by a double click. The diamonds
between the color fields change the interpolation between the respective
colors.
- The arrow at the right border allows to call advanced functions (see
chapter 3.4.6.1 and following).
- The gradient type
- There are four gradient types: Linear, Circle, Radial mirrored and
Radial.

Applying
a Gradient
To apply a gradient, you draw a line in the image with the mouse, indicating
the start and end points of the gradient. The border beyond that is filled with
the starting or ending color.
Gradients can be constrained by the mask.
Gradients can also be created in the mask by activating the Edit Mask icon
(see chapter 4.5.2.4).
There is a special feature with the gradient tool when it is applied only to
transparency (A channel in the tool settings). In this case, the gradient’s
transparency overwrites the existing one and does not add to it as usual.
If In Active Layer
is disabled, the gradient is not drawn in the active
image layer, but a new vector layer is created.
Post-processing a Gradient
After a gradient has been created, it can still be edited afterwards:
- Clicking and dragging changes the position of a color.
- Clicking on the gradient line creates a new color.
- By dragging away a color can be deleted. Note, however, that the
gradient must consist of at least two colors.
- The context menu for the gradient line allows you to change the gradient
type and color mode.
You can still edit gradients after switching to another layer or even after
saving and reloading the document. But to do this, the gradient must meet
certain conditions:
- The intensity must be 100%.
- All colors must be completely opaque.
- The gradient must be applied to all channels.
- The blend mode must be Normal.