Phenotypic (rP) and genetic correlations from polygenic components (rPOLY) for melanoma grade, grey level, vitiligo grade, and speckling grade estimated using different scenarios.*

*The first scenario is a polygenic model applied to data from all genotyped horses. The second scenario is a polygenic model that also includes STX17 (for all traits) and ASIP (only for melanoma grade), applied to data from all genotyped horses. The third scenario is the polygenic model applied to data only from homozygous (GG) horses, corresponding to 70–73% of the complete data set, depending on the trait.