Taupe is often mistaken for other shades of brown. A true taupe has no visible red undertone. It is a cool brown - leaning a little to the blue or lavender side of brown without the traces of yellow or orange you will find in a warm brown or a chocolate.
It is usually grayed down a little - like a Weimaraner. In fact as dogs go, Weims are true taupe - even referred to at times as gray ghosts because of their taupe hues and light eyes