Seal-brown is a unique and descriptive color that is often difficult to describe using words. However, there are several synonyms that can be used to accurately describe this color. For instance, cinereous is a term that refers to a deep grey-brown color that is similar to seal-brown. Another synonym for seal-brown is liver, which is a rich and dark brown color that has a hint of red. Chocolate brown is also a close match to seal-brown and is a rich, dark brown color that is often used in fashion and interior design. Finally, mahogany is a synonym for seal-brown that refers to a very dark brown color that has red undertones.