Aharoni–Barat–Wanless rainbow matching conjecture

Let $G$ be a bipartite graph, let $\Delta(G)$ denote its maximum degree, and suppose that every colour is used on more than $\Delta(G)+1$ edges. A rainbow matching is a matching whose edges have pairwise distinct colours.

Aharoni–Barat–Wanless conjecture. The graph $G$ has a rainbow matching using every colour.

This is another conjecture about rainbow subgraphs. It is disproved by the construction in the paper, which supplies a counterexample satisfying the relevant edge-colour multiplicity condition.