An image gradient is a directional change in the intensity or color in an image. The gradient of the image is one of the fundamental building blocks in image processing. For example, the Canny edge detector uses image gradient for edge detection. In graphics software for digital image editing, the term gradient or color gradient is also used for a gradual blend of color which can be considered as an even gradation from low to high values, as used from white to black in the images to the right. Another name for this is color progression.
A blue and green color gradient.
In color science, a color gradient specifies a range of position-dependent colors, usually used to fill a region.
RAL CLASSIC K5 color fan
cards of Pantone base colors and blends
HKS colour fan
conic gradient