It seems quite common for the plastic bumpers to look a slightly different shade to the bodywork nowadays.
As to the misalignment of the bumper, it does appear that the bumper was removed. The rear bumper on mine was removed when I had the trim sprayed. It is now misaligned like in the picture, despite some fiddling from the bodyshop. I think it is quite difficult to put the bumper back on straight if you don't have the knack.