Well that because taupe is all of those-- taupe is brownish grey-- but that leaves a lot of space since "brown" is really a wonderful hodge-podge color. it can be greenish, or redish, or blackish-- and then take what ever you have, and soften the color by adding grey--which at once makes it lighter (the white half of grey), and drabber, (the black half of the grey).
so everything from the color of cooked mushrooms--or earth soiled sail (white) cloth, or patches of sycamore bark could be called 'taupe' as could khaki-- which is from the hindu for "the color of the dust of the earth"
depending on where you are-- khaki is a very different color. from very light to rather dark, from brownish red, to almost white or green-- to taupe!
Puce is another one of these colors that is kind of hard to define-- its dark reddish brown... but it could be the color of Rose bush leaves-- not the pure green one, but the leaves that have a reddish/brown/green color-- which doesn't sound like it could be a color-- but somehow, rosebushes manage it!
