Here are pictures of the one I have found:
The roof on the right hand side compared with a normal one on the left and another slightly faded one in the middle:
The interior compared with a normal one:
I am sure that mine is a sunfade mainly because there were others on that same table and because the interior and roof have both been affected. If this were a genuine factory-made variation, it would be very unlikely to get two separate components in unusual colours on the same model.
(BTW no idea about the significance of the black spot on the bottom of the tow hitch. It will not come off just with water and soap, and I do not want to try anything stronger.)
I will not pass judgement on other examples, as I simply do not know for sure. Everyone is free to judge for him/herself!