In the automatic coloring of SOM framework, Kaski et al 14, 15 propose to embed data in a CIELab colorimetric space. 16 Properties of this colorimetric space also fit very well with our context: indeed distance between positions in the CIELab colorimetric space is supposed to be linked with the human perception of color difference. However, significant constraints are placed on the mapping due to the particular shape of the CIELab space. In contrast, the mapping on circleshaped HSB sub-space is easier. Most of the times, data can be expected to fill a large part of the space after a simple rescaling procedure. Moreover, the mapping can be easily rotated and returned in the space in order to find the most convenient color code.