The Standard Reference Method, abbreviated as SRM is the color system used by brewers to measure the color of finished beer and also malts. SRM is historically related to the British measurement Lovibond, and the two systems are equivalent for home brewing applications. SRM is also sometimes referred to Standard Research Method by some books. Below are some approximate SRM color ranges.
1.0 - 3.0 SRM - Pale yellow color 3.0 - 4.5 SRM - Medium yellow 4.5 - 7.5 SRM - Gold 7.5 - 9.0 SRM - Amber 9.0 - 11.0 SRM - Copper 11.0 - 14.0 SRM - Red/Brown 14.0 - 19.0 SRM - Brown 20.0 SRM - Black
A separate color system, called the European Brewing Convention (EBC) is used to measure beer color in some places in Europe.