The two coloring of the edges of
K_{48} which established the lower bound is
available as a 0-1
adjacency matrix
in which color 0 is K_{4}-free and color 1
is K_{7}-free.

This was a two step construction. First a circulant graph was found with relatively few bad subgraphs, then via simulated annealing, the bad subgraphs were eliminated.

Geoff Exoo