The above research field is yet relatively unexplored. An automatic coloring tool for tree exploration has been proposed by Fua and co-authors: 5, 6 in order to explore a given taxonomy, leaves are considered as an ordered list of items (the order can result for example from the reading direction when the tree is displayed on a phylogram). Each node can then be related to a color according to a chosen LUT (Look-Up Table) . The LUT may be locally stretched or compressed in order to focus on a given area. Such an interactive control of the LUT allows exploring the taxonomy while considering various depths. This approach suffers however from a major shortcoming: the leaf ordering is not unique (trees are invariant with respect to permutation of linked branches). Very different colorings can then result from various choices. Moreover, close colors can correspond to items that belong to different branches and somewhat different colors can rely to close species. These drawbacks can be observed in Figures 6 and 8 .