Shapes Bevel

i plugged an elipse with a solid, one color circle into a polygon color node set to contours. using just those two components, i couldnt eliminate the gradient edges of the resulting 'donut'. if i wanted a solid edge i had to use more components. this strikes me as odd and i believe that the culprit is the bevel control, at least on the polygon and perhaps the elipse as well. what the bevel is actually doing in this case is controlling the inner radius and not the bevel at all. the bevel shld control the gradient edge, going from a gradient, soft edge to a hard, solid edge and another control would control the radius of the inner edge.