Note on robust coloring of planar graphs

Authors:
  • FKFrantišek Kardoš
    František Kardoš
  • BLBorut Lužar
    Borut Lužar
  • RSRoman Soták
    Roman Soták

Abstract
We consider the robust chromatic number $χ_1(G)$ of planar graphs $G$ and show that there exists an infinite family of planar graphs $G$ with $χ_1(G) = 3$, thus solving a recent problem of Bacsó~et~al. (The robust chromatic number of graphs, Graphs Combin. 40 (2024), #89).