I've noticed that in my cat also. She's mixed, but looks like this one:http://www.traditionelesiamezen.nl/l...hadderingh.htm
I got her from a shelter, andthey said she was 4 y o.
Around May she was all a dark choc. head and back - with cream legs, and lower down, she had beautiful dark brown booties (I think cat feet are the most perfect things). But I noticed around Oct. she was starting to get gray starting from the back of her head, and her back now looks gray and the sides of her body.
I wonder if it has to do with the time of year, like a fox changing colors?