No Don
As I grew up on a farm surrounded by Fresians, I can answer this quite authoritively.
The Northern Worcestershire British Fresians are a cross breed between the African Zebra and Outer Mongolian Yak with a little Mountain Goat thrown in for good luck. The animals are actually black with white patches added later as opposed to being white with black patches. As the black is solution dyed during copulation, there is no chance of colour loss. The white is not quite stable but as the black is a solution pigment, there is no risk of this being compromised.
On the other hand, someone else may know otherwise......
Safe and happy cleaning
Ken
PS Don, Had you used to sniff too many CO
2 bubbles?