Gum bichromate negatives of cyan, magenta, and yellow or red, green, and blue are used for a full-color image. Some photographers prefer substituting the cyan emulsion in the CMYK separations with a cyanotype layer. A simple duotone separation combining orange watercolor pigment and a cyanotype can yield surprisingly beautiful results. Low density photographic negatives of the same size as the final image are used for exposing the print. No enlarger is used, but instead, a contact printing frame or vacuum exposure frame is used with an ultraviolet light source such as a mercury vapor lamp, a common fluorescent black light, or the
Blue–green distinction in language "siwy" means blue-gray in Polish (literally it means the color of gray hair). The word "siny" refers to violet-blue and is used to describe the color of bruises ("siniaki"), hematoma, and the blue skin discoloration that can result from moderate hypothermia. Russian does not have a single word referring to the whole range of colors denoted by the English term "blue". Instead, it traditionally treats light blue (голубой, "goluboy") as a separate color independent from plain or dark blue (синий, "siniy"), with all seven "basic" colors of the spectrum (red–orange–yellow–green–голубой / "goluboy" (sky blue, light azure, but "does not equal"