Vanishing ebony

[Binki]

Hope for some help in solving this mystery,
About a month ago I rescued male chin who looked to me (no expert in chin genetics and previously only had beiges) like an ebony carrier, with a white tummy, a very black triangle on the head and a black back. What baffles me is that he is looking more and more like a standard: starting on the head the black is vanishing, the coat becoming more veiled in white. His rump is still black but perhaps not for long.
He has no health issues, is friendly, happy and loves his food. The only change is that because his paws were always cold (as it is my house, even in summer) and he has completely ignored his fleecy hammock, two weeks ago I moved his cage within the peripheral range of a radiator at a temp around 16 °C. Coudl that have an effect on his fur? I did the same with my beiges but their coats never changed; or not noticeably, at least.
Do chins take pleasure in baffling their owners?

 

[Amethyst]

Is one of the parents ebony and that is why you think it's an ebony carrier? From what I understand if he is a standard grey ebony carrier the belly wouldn't be pure white it would be more a light greyish color. Standard greys come in different shades too they don't all look exactly the same, normally black to dark grey on the back going grey on the sides with a white belly. Actual ebonies are solid color (ranging from light grey to jet black), no white belly. If you post a pic that might help tell what color he really is. I doubt changing where the cage is would change the fur color, but some chins do lighten or darken in color as they go from kit coat to adult coat.

 

[Binki]

Thank you for your response. I rescued him from an animal shelter so I know nothing about his parents. I assumed he had one ebony parent because his coat was very dark when I got him and none of the standard chins I had seen thus far (admittedly not many; mine were all beiges) had solid black backs. And then he started to get lighter.

I managed to get two photos that show quite accurately (the light patch on the side photo 1 is a reflection from the flash) how the white veiling is progressing towards the back. I was told he is between 1-2 years old and he is a big boy (650 g). And yes, he has a white tummy.

 

[Amethyst]

Yeah, he just looks like a dark standard grey to me. Here is a good rundown of what the different shades of standard grey look like Standard Gray Chinchilla Pictures

 

[Binki]

Many thanks for the link: excellent description of the variety of shades standards can have. All the sites I had visited before gave a much more perfunctory description, so I believed standards meant looking like the very few chins now left in the wild.