Mixed Hypergraph Coloring
Classical coloring theory studies the problem of determining the minimum number of colors required for a proper coloring.
The fundamental idea of mixed hypergraph coloring is to introduce, in the most general setting, the dual problem of determining the maximum number of colors, and to combine it with the classical approach.
The main conclusion is that, although one may expect a formal symmetry between these two opposite constraints, there exists a deep asymmetry between problems concerning the minimum and maximum number of colors. This asymmetry permeates the theory, methods, algorithms, and applications of mixed hypergraph coloring.