This chapter highlights some of the fundamentals of color science, colorimetry, color technology, and color systems. It presents a progressive introduction of principles from a logical rather than historical perspective. The chapter summarizes the understanding in the areas with particular emphasis on the aspects that are of interest in color imaging applications. It provides an overview of color recording and reproduction devices, their underlying physical principles, and color characteristics. The chapter describes the concepts of device-independent color and color management. It explains a system for specifying color in terms of tristimulus values that can be used to represent colors unambiguously in a three-dimensional space. The chapter discusses the fundamentals of color science and technology as applied to color digital imaging. It attempts to provide a systems view of color imaging systems, where the interactions between image capture devices, image and color processing operations, image display and printing systems, inherent characteristics of natural and man-made images, and the human observer.