Hi everyone! This is my first post on these forums. 
In case you haven’t heard about it before, spectral rendering is using a continuous spectrum of wavelengths to model lighting, instead of separate R, G, and B channels. Some more info can be found on Wikipedia: Spectral rendering - Wikipedia
and in this SE answer: color - Are there common materials that aren't represented well by RGB? - Computer Graphics Stack Exchange
The most common real world effects that inspired me to ask this question are the thin film rainbow effects found in soap bubbles, and the dazzling iridescence of certain animals when viewed under the right lighting conditions.
Right now I haven’t seen any engine that can deliver convincing simulations of such effects. It probably would be too costly for real time rendering at high frame rates, but it might be doable in the near future at 30 fps. Though of course this is just a hunch as I’m a total newbie in engine design.
Has anyone heard more about this?