The color is also called isabella. Does that make
Isabella gross too?
Anyway, according to the Oxford English Dictionary, the word isabelline to describe the tawny color of animals was in use before the Siege of Ostend involving
Queen Isabella, so that etymology is disputed. Another theory speculates that the word is a corruption of zibellino, a sable pelt accessory that was popular around the time the word first appeared, or it might be from the Arabic word for lion, izah, to mean lion-colored.
Regardless of the possible etymology, it's mainly used to describe the tawny color of animals, for instance to describe the color of cremello horses. Which isn't a bad meaning.