  Recent investigations in computational biology focus on a family of 2-colored
digraphs, called 2-colored best match graphs, which naturally arise from rooted
phylogenetic trees. Actually the defining properties of such graphs are
unexpectedly unusual in graph theory, and they were established only recently
after the discovery of their links to evolutionary relatedness via phylogenetic
trees. In this paper several results are obtained on 2-colored best match
graphs which well fit in the mainstream of graph theory.
