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.