2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/141067In this short note we prove that there is a constant $c$ such that every k-edge-coloring of the complete graph K_n with n > 2^{ck} contains a K_4 whose edges receive at most two colors. This improves on a result of Kostochka and Mubayi, and is the first exponential bound for this problem.9 pagesCombinatoricstext