Colors are a way of communication that emphasizes the information of a given illustration. Therefore color faithfulness is evident. To know if a given color is within a special color gamut first of all this gamut needs to be known.To calculate the color gamut of a device a number of solutions have been suggested. Most of them are dealing with the fact that they over- or underestimate the real volume of the color gamut, respectively.Our approach applies a grid onto the hull of the color volume. Using this approach a very accurate information about the border is received independently of a convex or non-convex shape. Having got this basic grid information it comes out that a cut at a given L* value can be calculated. Therefore for a given color value a slice of the color gamut can be calculated and the relative position can be obtained.Using this procedure it is also possible to determine the volume of the color gamut.