This trait can allow for simple color changes, such as WHIFF-100's color changing mane (green -> brown). Can be an effect of the seasons as well. Is not a direct control of magic to change said markings' colors.
These include little floating objects seperate from a Whiffling's body relating to their scent, see Rainwater's rainclouds. They're more illusory than anything, but can have small effects (like causing small rains near them).