Abbreviation referring to the four inks used in color printing: Cyan, Magenta, Yellow, and Key black. According to some, black ink is called K (key) because the four colours are aligned with the key of the black key plate, the plate that contains more details to be printed. According to others, the K comes from the last letter in black and was chosen because B already means blue: but blue is not a primary colour, cyan is.
The correct pronunciation