The development of wideband lasing media has deep implications for imaging,sensing,and display technologies.We show that a single chromophore can be engineered to feature wide-gamut fluorescence and lasing throughout the entire visible spectrum and beyond.This exceptional color tuning demonstrates a chemically controlled paradigm for light emisSion applications with precise color management.Achieving such extensive color control requires a molecular blueprint that yields a high quantum efficiency and a high solubility in a wide variety of liquids and solids while featuring a heterocyclic structure with good steric access to the lone pair electrons.With these requirements in mind,we designed a lasing chromophore that encloses a lasing color space twice as large as the sRGB benchmark.This record degree of color tuning can in principle be adapted to the solid state by incorporating the chromophore into polymer films.By appropriately engineering the base molecular structure,the widest range of lasing wavelengths observed for a conventional gain medium can be achieved,in tu establishing a possible route toward high-efficiency light emitters and lasers with near-perfect chromaticity.