Royal palms are black-wing bronze based with double recessive gray and Narragansett genes, or b1b1cgcgngng, where b1 is the black wing gene, cg is gray, and ng is Narri.
A sweetgrass b1b1cgcgNgNg x black BBCCNgNg. (Black based with not white genes and not Narragansett genes) would have a...