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
Combination printing often necessary to add artistic techniques to photographs. Discussing the benefits of composition in the art of photography and using combination printing, Robinson wrote, in "Pictorial Effect in Photography", that the method of combination served to "produce an agreeable presentation of forms and tones, to tell the story which is to be elucidated, and to embody the spirit of what it is intended the picture shall represent or suggest." His writings show his knowledge and his passion for creating new content in his photos with using this process. During the Victorian Era, another proponent of the technique of combination printing