In an effort to further establish identity and promote a standard, many institutions often decree the use of specific shades of colors. Maroon, generally regarded as a darker shade of red, is a common primary color. Various shades of blue, from powder to Prussian, are also in use; a few schools have adopted two different shades of blue for their colors, with the darker shade serving as the primary. The shade of gold can vary greatly even within an institution, from a vivid yellow to a more convincing old gold.