Dark Coated Siamese Cats
Sometimes you see Siamese cats that have dark fur on their torso area. The contrast between the body and extremities is much reduced.
This occurs in older cats because of poor blood circulation. This results in the body being cooler which in turn leads to production of pigmentation in the skin that goes into the hair shafts.
I am guessing too that in cooler climates there might be darker fur in the torso area.