The authors introduce a family of photo-switchable fluorescent probes and demonstrate multicolor stochastic optical reconstruction microscopy (STORM) to achieve super-resolution imaging with a spatial resolution of 20-30 nm. Each probe consists of a photo-switchable "reporter" fluorophore that can be cycled between fluorescent and dark states, and an "activator" that facilitates photo-activation of the reporter. By combinatorially pairing reporters and activators, the creation of probes with distinct colors is possible. Iterative, color-specific activation of sparse subsets of these probes allows their localization with nanometer accuracy, enabling the construction of a super-resolution STORM image. The technique is demonstrated using multi-color imaging of DNA model samples and mammalian cells, showing clear separation of molecular interactions at the nanometer scale. This approach significantly enhances the ability to visualize molecular interactions in cells and tissues.The authors introduce a family of photo-switchable fluorescent probes and demonstrate multicolor stochastic optical reconstruction microscopy (STORM) to achieve super-resolution imaging with a spatial resolution of 20-30 nm. Each probe consists of a photo-switchable "reporter" fluorophore that can be cycled between fluorescent and dark states, and an "activator" that facilitates photo-activation of the reporter. By combinatorially pairing reporters and activators, the creation of probes with distinct colors is possible. Iterative, color-specific activation of sparse subsets of these probes allows their localization with nanometer accuracy, enabling the construction of a super-resolution STORM image. The technique is demonstrated using multi-color imaging of DNA model samples and mammalian cells, showing clear separation of molecular interactions at the nanometer scale. This approach significantly enhances the ability to visualize molecular interactions in cells and tissues.