All of the apparent drastic color differences in the robot from one picture to the next are just the result of my crappy photography skills and the changing light in the studio. I've really changed almost nothing on the actual robot except to add some very pale blue to the light areas.
I found a Silver Surfer toy in a thrift store and some kind of hubcap thing on the ground. Both are useful visual references for painting this kind of thing. although in this photo they're sitting on a blue box in a warm colored room so the color is opposite of what I've showed you. I took them outside a few times to get a better idea of how the reflections should look.