[R] response surface designs

[Dmitry Gospodaryov]

How I can obtain graphics for response surface design,
basing on data:
x: 0.25, 1, 4, 10, 20.
y: 0, 0.5, 1
z1 (for y = 0): 45, 35, 25, 15, 10.
z2 (for y = 0.5): 50, 45, 36, 21, 17.
z3 (for y = 1): 37, 34, 22, 17, 11?
z-values should be scaled in colour (e. g. from red to blue).
I consider to use packages "rsm" and "graphics"
(with "grDevices"). I suggest to use Box-Behnken design
in "rsm" and filled.contour in "graphics". However,
I do not know how I can combain these two opportunities.
I am not familiar in response surface analysis, and able
to be wrong in the selection of the model. Thank you
for any reply. With regard, Dmitry.