I wasn't talking about the band color but the color of Space Gray vs. Silver body. If someone posts a real-life photo of the back of either one, it's really difficult to tell unless we see the front (black vs. white face).
The band color on the Space Gray model does change depending on the viewing angle and lighting. As a result, it can be darker or lighter than the body. The OP was asking why the Space Gray body is so much darker in the render than in real life. "Dark space grey" were his exact words.
Your suggestion doesn't sound plausible to me, but we'll have to agree to disagree about our speculations.
If you look at subsequent posts (specifically number 4 in this thread) he is referring to the bands...