I am powerfully attracted (only insofar as the snip allows) to tortoiseshell (or calico) cats. I love that mixture of black and ginger. I particularly love the little straight line down the face with ginger one side and black the other. Cutest of the cute.
"Naughty Torties" is what tortoiseshell cats are always called. Maybe there is some difference in behaviour between colours but it is possible the lighter shades of cat are more friendly, because they are picked up and cuddled more as kittens. Cat rescuers don't mean to do this, but sometimes the unpopular colour kittens (black and brown) get less attention. So they grow up less cuddly. It would be very difficult to prove....
To be a tortie, you have to be female with a double X sex chromosome, XX, or a rare chimera male with an extra female chromosome X, ie an XXY. Males (XYs) with the dominant ginger allele are all over ginger because they only carry one X gene. Female have two XX genes and one is randomly inactivated in each cell in favour of the black or brown producing the tortoiseshell coat.Various other coat colour genes then add white or dilute the colours.
I shall post some photos of my favourtite torties with their two-sided faces