The charter of the Commission Internationale de l'Eclairage (CIE) Division 8 Technical Committee 5 is to recommend a “minimal set of techniques that enable unambiguous and efficient communication of the color information in images,” including defining “a minimal set of standard color spaces that addresses a wide range of imaging applications.” One of the main activities of this committee to date has been the development of a series of objective tests that can be used to compare the characteristics of different color encodings. This paper will describe a number of metrics that have been developed relating to color gamut and color quantization. Example results are presented where these metrics have been applied to a number of recently proposed color encodings: sRGB, e-sRGB, sYCC, e-sYCC, ICC PCS, and ROMM RGB.