Are zebra stripes black or brown?

Depending on the species and age, zebras can have stripes that range in color from black to different shades of brown. There are three species of zebra: Grevy’s, mountain, and plains. All wild zebras (i.e., those not living in zoos) live in different habitats in Africa. Each species can be identified by body size, shape of certain body features (e.g., ears), and stripe pattern and color. Note that there are also subspecies, which are groups of a species of zebra that have unique features or living habits that make them different from groups of the same species living in different areas.
Stripe patterns within the same species will have certain similarities. However, there is enough variation so that each individual zebra has a unique stripe pattern, somewhat like a human fingerprint. Researchers are able to use these stripe patterns to help them identify individual zebras they study in the wild.
Zebra stripes are typically identified as the dark colors of the patterns on the body, not the white areas. The stripes of adult Grevy’s zebras are black, but young Grevy’s actually have stripes that are reddish-brown. This color begins to change to black as they grow older. Mountain zebras can have black or dark brown stripes. Adult plains zebras have stripes that also can be black or brown, and some are known to have what is called a “shadow” stripe—a brown color in the white area between the darker stripes. The stripes of very young plains zebras are lighter than adult stripes, with colors described as buff, brown, or a “dusty” version of the darker adult colors.
Further Reading:
http://animals.sandiegozoo.org/animals/zebra
http://animaldiversity.org/accounts/Equus_burchellii/

https://animaldiversity.org/accounts/Equus_grevyi/

https://animaldiversity.org/accounts/Equus_zebra/