[Solved] cycles color ramp ?

i tried to make some mat for cycles with nodes
and was not able to get coloramp to work!
also the refraction node did not work!

like

Gamma1 = m1.makeNode(‘ShaderNodeGamma’, ‘Gamma1’)
Gamma1.location =-900, 150

is there a way to make some color ramp and specifying the bands also?

thanks