Each position in the mapping can now be related to a color according the HSB (Hue, Saturation, Brightness) colorimetric conic-shaped space (The HSB space is also called HSV space (V for Value) or HSL space C is linked to node N 1 by node N 2 (similarly to the example in Fig. 3) . d(x, y) corresponds to the distance between elements x and y in the tree. According to the properties of geometric progression with a common ratio equal to 1/2 (basically,