Why is Himalayan Salt Pink? I have heard it is from an ancient ocean floor's deposits that have since been uplifted by the Himalayan orogeny, but what in that ocean water made the salt pink. I've been to the Bonneville Salt Flats and the salt there is a normal white color.

Other questions, for example Pink salt vs regular salt just concern the taste in dishes. I am concerned with the actual difference in chemical composition.
As stated in the Wikipedia article about the salt, the pink color that sometimes occurs is due to iron oxide:


  Himalayan salt is predominantly sodium chloride (95-98%), contaminated with 2–3% polyhalite and small amounts of ten other minerals. The pink color is due to the presence of iron oxide.


As a source, the article references this page on HowStuffWorks.com. It gives a slightly broader list of chemicals that cause the color differences:


  Some pink salts, such as the salt harvested in the Himalayas, get their color from calcium, magnesium, potassium, copper and iron, Others contain carotene from salt-tolerant algae and are more peach-colored.