I'm using Blender 2.80. Start in a new scene with no objects. Add a sphere, then go to the Properties panel, Material tab, and set the Base color to pure red in the Principled BSDF. Next, run this script:
import bpy # Get current active object ob = bpy.context.active_object # Set the material diffuse color ob.material_slots.material.diffuse_color = (0.0, 0.0, 1.0, 1.0)
When I do this, the color of the sphere changes to blue in the viewport. However if I do a render with F12, the color of the sphere is still red. How can I set the material color for rendered images?