Ultra‐broadband luminescent sources that emit light over an extremely wide wavelength range are of great interest in the fields of photonics, medical treatment, and precision measurement. Extensive research has been conducted on materials doped with rare‐earth and transition‐metal ions, but the goal of fabricating an ultra‐broadband emitter has not been attained. We present a facile method to realize this kind of novel light source by stabilizing “active” centers (bismuth) in a “tolerant” host (nanoporous silica glass). The obtained highly transparent materials, in which, unusually, multiple bismuth centers (Bi+, Bi2+, and Bi3+) can be stabilized, emit in an ultra‐broadband wavelength range from blue‐green, orange, red, and white to the near‐infrared region. This tunable luminescence covers the spectral range of the traditional three primary colors (RGB) and also the telecommunications windows.

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Here, tuning of the optical properties of emission centers by tailoring the ligand fields is investigated. Experimentally, it is demonstrated that Ni2+ can act as a single emission species in multiple octahedral local environments. Nanocrystal‐embedded hybrid materials are employed as hosts in order to take advantage of their convenience in local environment design for practical applications. Novel composite gain materials with high transparence are successfully made, and show interesting wavelength‐tunable and ultra‐broadband infrared luminescence covering the whole near‐infrared region from 1 100 to 1 800 nm. The infrared luminescence peak positions can be finely tuned from 1 300 to 1 450 and to 1 570 nm, with the largest full width at half maximum being about 400 nm and covering the telecommunication bands at 1 200–1 500 nm. According to the results of characterization, the unusual luminescence, interestingly, originates from Ni2+ in nanocrystals and the doping efficiency of Ni2+ is surprisingly high. The results demonstrate that the method presented may be an effective way to fabricate multifunctional light sources with various fundamental multifunctional applications from efficient broadband optical amplifiers to bio‐imaging.