Abstract: Circuitry for converting digital red, green, blue (RGB) inputs into digital saturation and hue outputs comprising hardwired digital components connected to receive the digital RGB inputs and to perform arithmetic manipulations of them so as to provide a digital saturation output representing saturation for the RGB inputs and to provide a digital first intermediate output, and a first look-up memory storing digital hue data representing hue of the digital RGB inputs at addresses corresponding to values of the digital first intermediate output, the look-up memory being connected to the hardwired digital components to be addressed by the digital intermediate output, the memory providing a digital hue output.