Grey on televisions, computer displays and telephones is usually created using the RGB color model. Red, green, and blue light combined at full intensity on the black screen makes white; by lowering the intensity, it is possible to create different shades of grey. In printing, grey is usually obtained with the CMYK color model, using cyan, magenta, yellow and black. Grey is produced either by using black and white, or by combining equal amounts of cyan, magenta and yellow. Most greys have a cool or warm cast to them, as the human eye can detect even a minute amount of color
RG color space replicated accurately in the RG color space. There is a similar color space called RGK which also has a black channel. Outside of a few low-cost high-volume applications, such as packaging and labelling, RG and RGK are no longer in use because devices providing larger gamuts such as RGB and CMYK are in widespread use. Until recently, its primary use was in low-cost light-emitting diode displays, where red and green tended to be far more common than the still nascent blue LED technology, though full-color LEDs with blue have become more common in recent years. ColorCode 3-D, a stereoscopic color