De Grey pitched the problem of finding the minimal five-color graph to Terence Tao, a mathematician at the University of California, Los Angeles, as a potential Polymath problem.

But that doesn't mean five is the absolute minimum. Mathematicians know that it's possible that a graph will come along requiring six colors of paint, or even seven.

Graph reconfiguration and colouring problems investigate the transition between feasible solutions of a graph colouring instance. The central challenge is to determine a series of elementary ...

B-Chromatic Number and Graph Coloring Publication Trend The graph below shows the total number of publications each year in B-Chromatic Number and Graph Coloring.