This Standard Practice deals only with simplified color indices applicable specifically to white colors. There are approximately 5000 distinguishable white colors. As with any other color, three numbers are necessary for the complete identification of any white. All the color and color difference scales regularly used for color specification are applicable to white colors.
ANSI/TAPPI T1216 sp-2012 history
2012ANSI/TAPPI T1216 sp-2012 Indices for whiteness, yellowness, brightness, and luminous reflectance factor