Test that checks the capability of the stop element in linear and radial gradients.
From top-down the appearance of objects is as follows.
The first rectangle has a linear gradient fill with a vector starting at top left and going to bottom right. The stop colors are at 20% spacing apart and are in the following order : violet, blue, lime, yellow, orange, red.
The next rectangle has a radial gradient fill with a multi-color stops from innermost to outermost in the following order : black, yellow, red, blue, white, green.
The rendered picture should match the reference image exactly, except for possible variations in the labelling text (per CSS2 rules).