Tertiary color secondary colors: orange-green, green-purple, purple-orange; or by intermixing complementary colors. This approach to tertiary color relates specifically to color in the form of paints, pigments and dyes. The primary colors in an RGB color wheel are red, green, and blue, because these are the three additive colors—the primary colors of light. The secondary colors in an RGB color wheel are cyan, magenta, and yellow because these are the three subtractive colors—the primary colors of pigment. The tertiary color names used in the descriptions of RGB (or equivalently CMYK) systems are shown below. The primary colors in an RYB color wheel
RG color space replicated accurately in the RG color space. There is a similar color space called RGK which also has a black channel. Outside of a few low-cost high-volume applications, such as packaging and labelling, RG and RGK are no longer in use because devices providing larger gamuts such as RGB and CMYK are in widespread use. Until recently, its primary use was in low-cost light-emitting diode displays, where red and green tended to be far more common than the still nascent blue LED technology, though full-color LEDs with blue have become more common in recent years. ColorCode 3-D, a stereoscopic color