When you ask whether zebras are black or white, that's actually a serious question and it has an answer. Zebras are black with white stripes. All the fur grows from follicles that contain the pigment-generating melanocyte cells. Melanocytes are the cells that produce melanin, which gives fur its color. Melanin is found in the skin of all mammals (including humans). It protects skin from the sun and UV radiation, and helps keep the skin healthy. In general, more melanin means darker skin. However, in the white fur, those melanocytes have been deactivated. This implies that black is the default colour of the fur and most scientists describe zebras as black with white stripes.