Why is p**p brown? Not to sound vulgar..?

Question

The topic says it all..

Answer 1

Why is p**p brown?

    The color comes mainly from bilirubin, a pigment that arises from the breakdown of red blood cells in the liver and bone marrow. The actual metabolic pathway of bilirubin and its byproducts in the body is very complicated, so we will simply say that a lot of it ends up in the intestine, where it is further modified by bacterial action. But the color itself comes from iron. Iron in hemoglobin in red blood cells gives blood its red color, and iron in the waste product bilirubin gives rise to its brown color.

Answer 2

Man Heidi, more info on the subject that I ever thought I'd  learn!  Good, informative answer!