do red fox change color in the winter
Yes,  A typical colouration in red foxes usually represents stages toward full melanism, and mostly occurs in cold regions.
Red fox
Atypical colouration in red foxes usually represents stages toward full melanism, and mostly occurs in cold regions.
wiki:8691047
Red fox [SEP] Colour morphs
Atypical colouration in red foxes usually represents stages toward full melanism, and mostly occurs in cold regions.