Fulvous [Adj] a colour: “sometimes described as dull reddish-yellow, brownish-yellow or tawny, it can also be likened to a variation of buff, beige or butterscotch. As an adjective it is used in the names of many species of birds, and occasionally other animals, to describe their appearance.”
The first recorded use of fulvous as a colour name in English was in the year 1664. I believe it is also used by Edgar Allen Poe in “Murders in the Rue Morgue”.
I was recently looking up duck species because there are many, many of them currently flocking around the inner harbour and came across this word and didn’t know what it meant. However, now when I am reading about the Fulvous Whistling-duck, I will know they really mean tawny. Tawny Whistling-duck. (All I wanted to know was whether the birds I saw were actually Mergansers, as I had originally thought. I was right!)