Gradient shading is applied on top of everything. There are three gradient modes, Linear Gradient, Radial Gradient, Corner Gradient
Linear Gradient #
You can have a gradient of 8 colors and 8 alpha keys and it will be applied linearly. You can change the rotation of the gradient.
Radial Gradient #
You can have a gradient of 8 colors and 8 alpha keys and it will be applied radially.
Corner Gradient #
You can have 4 colors with alpha for 4 corners of the image. These four colors are linearly blended.
Fixed and Blended Gradient #
In the gradient picker window, you can choose the gradient mode.