I have encountered an error with plots:-pointplot. > plt:=plots:-pointplot([ [1,1],[2,2] ],color=[COLOR(HSV,1,1,1), COLOR(HSV,1/2,1,1)],style=point,symbol=solidcircle,symbolsize=15); plt := PLOT(POINTS([1., 1.], [2., 2.]), STYLE(POINT), SYMBOL(_SOLIDCIRCLE, 15),COLOR(RGB, Array(1..6, [...], datatype = float[8]))) As you see the input list is using the HSV scheme but in the output it has been switched to RGB. This of course is reflected in the actual plots.