Bistre (or bister) is both a brown pigment made from soot, and the general name for a color resembling the pigment. Bistre's appearance is generally of a mid-to-dark warm brown, with a yellowish cast.
Beechwood was commonly burned to produce the soot, which was boiled and diluted with water. Many of the "Old Masters" used bistre as the ink for their drawings. Instead of this, some used the strokes of a pen, some Indian ink, others a black stone, etc.