In contrast to the device-dependent colour spaces RGB or CMYK, the CIELab colour space describes colour objectively, i.e. the colour values are thus clearly and unmistakably defined. The Lab color space separates the brightness (L) from the two color coordinates a- (red-green) and b-axis (yellow-blue). In addition, this color space includes all color impressions perceptible by the human eye, which are represented in it with approximately equal visual distance. An equal distance between two points results in a nearly equal sensation for the color difference of these two colors everywhere in this color space.
Light inks have a lighter concentration. It is usually only a dilution of the respective base colour. They are mainly used to achieve pastel shades on large areas in order to partially solve the problem of visible graininess caused by dithering.