Real Dictionary

umber
colour: Umber is used to describe things that are yellowish or reddish brown in colour.

umber in American English
noun: an earth consisting chiefly of a hydrated oxide of iron and some oxide of manganese, used in its natural state as a brown pigment (raw umber) or, after heating, as a reddish-brown pigment (burnt umber)

umber in American English 1
a kind of earth containing oxides of manganese and iron, used as a pigment: raw umber is yellowish-brown; burnt, or calcined, umber is reddish-brown
of the color of raw umber or burnt umber
to color with or as with umber

umber in American English 2
shade; shadow

umber in British English
adjective: of, relating to, or stained with umber
noun: any of various natural brown earths containing ferric oxide together with lime and oxides of aluminium, manganese, and silicon