Predicting the color polymorphism of ROY using optimally-tuned screened range-separated hybrid functionals

5-methyl-2-((2-nitrophenyl)amino)thiophene-3-carbonitrile is known to crystallize in various polymorphs that can exhibit different shades of red, orange, or yellow, earning it the nickname ROY. While spectacular, this color polymorphism corresponds to relatively modest spectral changes and is a long-standing challenge for time-dependent density functional theory. Here, we show that the experimentally observed ROY colors can be predicted using non-empirical optimally-tuned screened range-separated hybrid functionals.