Graph Coloring: The process of assigning colours to vertices or edges of a graph so that adjacent elements have distinct colours, commonly used in scheduling and resource allocation problems.

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 colouring is a fundamental problem in both theoretical and applied combinatorics, with significant implications for computer science, operational research and network theory. At its essence ...

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.

Graph coloring has been employed since the 1980s to efficiently compute sparse Jacobian and Hessian matrices using either finite differences or automatic differentiation. Several coloring problems ...