[vtkusers] Real colours in 3D CT image(DICOM)

[Bill Lorensen]

I think you are getting the correct image according to the code:

SetColor() sets the Ambient, Diffuse, and Specular colors.
in your case, SetColor(.75,.75,.75) sets each of those colors to grey.
Then, you call:
SetAmbientColor(.75, .10, .25);
since the Ambient coefficient (SetAmbient()) is 0 by default, the
SetAmbientColor(.75, .10, .25) has no effect.
SetDiffuseColor(0.75, .04, .025);
is a reddish color and since the Diffuse coefficient is .75,
SetDiffuse(0.75), it has .75 contribution to the final color.