Randomize renderer color/materials

[taiya]

new_mat = bpy.data.materials.new('Chrome')
new_mat.use_nodes = True
tree = mat.node_tree
[...]
o = bpy.context.object
o.active_material = new_mat

Control color as:

bpy.data.materials["Metal.002"].node_tree.nodes["Principled BSDF"].inputs[0].default_value = (0.749198, 0.297648, 0.249657, 1)

To duplicate materials:
https://blender.stackexchange.com/questions/82768/copy-material-with-python

[taiya]

Mapping of random colors to materials:

1. use colorsys

import colorsys
colorsys.hsv_to_rgb(random.random(), .3, .7)

2. use color_mode in ramp

  CR.color_ramp.color_mode = "HSV"
  CR.color_ramp.elements[0].position = 0.9
  CR.color_ramp.elements[0].color = color_hsv
  CR.color_ramp.elements[1].position = 1
  CR.color_ramp.elements[1].color = (0,0,0,1)

[taiya]

Ended up adding a "blender.MeshChromeMaterial" with configurable primary color.