3D color rendering

Mathcad 11 and eralier versions didn't render well the contour plot colors.

The first answer is: in Mathcad the contour plots are interpolated at a

maximum mesh 99. How could it render 256 colors ?

That's what the linear cone should render at right below.

Opps ! can't insert image [Error in the server ]

jmG

Maybe there is only one answer ?