Your browser window should be wide enough to see the arrow heads on each end of the red line below

The image below should appear as a rainbow starting and ending with red.
There should be a smooth transition from color to color with no banding and no little dots.

 

The image below is of 4 monochrome squares.  The top-left square should be absolute black, the bottom-right square should be absolute white while the top-right and bottom left squares should be a light gray without any colour cast.

 

The image below is a 10 step wedge, each step should be easily distinguishable from its neighbour.