OP-00253 Solution claimed A chromatic lower bound for positive-semidefinite nullity with SAP CO · Colin de Verdière parameters · graph colorings · OpenProblemsInNLA · strong Arnold property
OP-00328 Open Unbounded chromatic number of associahedron graphs CO · AIM Open Applied Problems · associahedra · flip graphs · graph colorings
OP-00377 Open Reed's bound for the chromatic number CO · AIM Open Applied Problems · chromatic number · graph colorings
OP-01090 Needs verification 3-colorability of great-circle arrangements CO · arrangements of great circles · graph coloring · The Open Problems Project · zonohedra