The trigonally coordinated [AuCu-(PPh(2)py)(3)](BF4)(2) (1) crystallizes in two polymorphs and a pseudopolyrnorph, each of which contains a trigonally coordinated cation with short Au-I-Cu-I separations of similar to 2.7 angstrom. Under UV illumination, these crystals luminesce different colors ranging from blue to yellow. The structures of these cations are nearly superimposable, and the primary difference resides in the relative placement of the anions and solvate molecules. As confirmed by time-dependent density functional theory calculations, it is these interactions that are responsible for the differential emission properties.