The -color
vertex Ramsey class
of a finite nonempty graph
is the class of graphs
for which every vertex coloring
with
colors contains a subgraph isomorphic
to
whose vertices all have the same color. These colorings need not be proper. The induced vertex
Ramsey class
instead requires a vertex-induced subgraph
of this kind.
Axenovich and Schmitteckert (2026) proved that for any two nonisomorphic finite nonempty graphs and every positive integer
,
and likewise
Thus either type of vertex Ramsey class determines its defining graph up to graph isomorphism.