In optics, orange has a wavelength between 585 and 620 nm and a hue of 30° in the HSV color space. In the RGB color space, it is a secondary color that is numerically halfway between red and yellow with gamma compression, as seen on the RGB color wheel. The complementary color of orange is blue. Orange pigments largely belong to the ocher or cadmium families and mainly absorb blue light. Varieties of the color orange can differ in hue, saturation (also known as saturation, intensity, or hue), or lightness (or value, hue, or lightness), or two or three of these qualities. Fluctuations in value are also called tints and tints, where tint is an orange mixed with white, or another tint where tint is mixed with black. Below is a large selection of these different colors.