Color Vision I: Color Matching
	u Elements of Color l Hue: refers to the color name we apply. l Saturation: purity of color, to desaturate add white l Brightness: u Trichromatic Theory of Vision l We have three classes of cones u L or red:    peak at 564 nm u M or green:     peak at 534 nm u S or blue:   peak at 420 nm