Number of colors

The visualization can be done alternatively with 2, 4, 6, 8, 10 or 12 colors (or intervals). The arrangement of the colors follows the solar spectrum. Cold colors correspond to values located below the arithmetic mean of the respective frequency distribution, warm colors correspond to values located above the arithmetic mean. Usually the psychologically best results can be obtained with 6 intervals, but in some special classification cases the choice of less or more intervals may be useful.