Techniques for rendering with illumination maps captured from real-world environments have provided the means to produce complex, realistic patterns of reflections in real-time computer graphics simulations. While the directional aspects of light emission and surface reflection are modeled comprehensively with these methods, the spectral component is typically represented with a three-channel RGB workflow. In this paper, we present a multispectral framework for capturing environmental illumination maps and incorporating them into a real-time rendering pipeline. The framework maintains two sets of trichromatic data through a real-time rendering workflow, using a six-channel representation optimized to allow for color-accurate relighting under a range of illuminants. We present the design of an end-to-end computer graphics color pipeline from capture to display, provide simulation results on the pipeline's colorimetric accuracy, and develop a prototype to demonstrate how the framework can be implemented in a GPU-based graphics shader architecture.