In summary, we have developed both a method of automatically generating active spaces and a variational method for choosing which one will perform best for vertical excitation energies. Our results show that the new method can enable the application of CAS-based approaches in a high-throughput and predictive fashion. Although one cannot guarantee that any single active-space selection method will always work well, variational selection with tPBE appears robust enough in selecting between wave functions, and so a mixture of different active space construction schemes in tandem with tPBE selection seems to be a promising approach.