linear-gradient
Yellow (top) to blue (bottom) [equivalent]
Yellow (top-left) to blue (bottom-right) [equivalent]
Yellow (top), blue, green (bottom)
Multiple overlapping gradients
Corner-to-corner, first: red (bottom-left), white, blue (top-right)
Repeating linear gradients
Red (left), white, blue (right). Should not show any grayish transition colors if the backend correctly interpolates in premultiplied alpha space.
Multiple locations per color