From the DNR Warden Wire Frequently Asked Questions:
Are white or albino deer protected and illegal to kill in Wisconsin?
Some are and some are not. Going back at least 75-plus years, white and albino were protected by law and could not be harvested by hunters. Many years later, a white deer was more clearly defined to be any deer that was all white, not including any part of the head, hooves or tarsal glands.
More recently, albino and all white deer were removed from the protected animal status in the Chronic Wasting Disease Management Zone (CWD MZ), allowing hunters to harvest such deer in the CWD MZ, as they are just as likely to contract CWD as any other deer.
Outside the CWD MZ, a deer that has some brown hair, even if only a small patch, on any part of the body that is NOT part of the head, hooves or tarsal glands, is not protected and may be harvested, tagged and registered by a hunter if they have a valid tag for that type of deer (buck or antlerless deer). Like hunting and harvesting any species of game, a hunter must be sure what they are shooting at is legal for them to harvest before pulling the trigger.