The HKS is a colour system which contains 120 spot colours and 3520 tones for coated and uncoated paper. HKS is an abbreviation of three German colour manufacturers: , , and . The association of those three companies have defined the colours of the HKS system since 1968. HKS colours, similar to Pantone colours, can be used in any kind of print publication to produce predictable colours. As in the Pantone colour system, there are HKS colours that cannot be reproduced using the CMYK colour space, like bright orange or certain tones of blue.