In Chapter 2, we dened the luminosity or perceived brightness of a color. Figure 2.10 shows a comparison between RGB hues at full strength or the highest luminosity. Typically, Reds, Greens, and Blues with high luminosity on an RGB display device are not easily reproduced using only CMYK ink or toner. Dening a color gamut for these respective systems helps us understand the variances in color ranges and determine optimal colors that will transfer eectively between devices. At present, there are no devices that can reproduce the entire visible spectrum of human color vision. Working toward this unrealized goal has resulted in improved color display, scanning and printing technologies.