Jack Cohen argued that a native Martian would not be a humanoid tall and thin (because of low gravity), with large chest (for breathing a thin atmosphere), covered in fur (because of the cold) because that is a human being adapted to Mars, not an organism that evolved on Mars.
But, if we are talking about human colonists of other planets, then maybe we can deduce some of their characteristics. In Larry Niven's Known Space future history, Jinxians have black skin from centuries of living under Sirius, not necessarily because their ancestors were African.
Poul Anderson's Daniel Holm, in the olive tunic and baggy trousers of a human member of the Ythrian armed forces, displays evidence of both mongoloid and caucasoid descent but what of the centuries that his more recent ancestors have spent on Avalon? I would expect that also to affect his appearance.