I want to be able to use the sliders on my photo editor, so that when I start with a shot where something in the shadows was too dark for my eye to see, I can still slide the brightness up and recover color. So that's imperative.

Moreover, a "color" is not simply an electromagnetic frequency. A color that is recorded by any receiver (living or mechanical) may be the combination of many light sources of different types (and frequencies) reflecting off of the same surface. Which is why lightbulbs get rated with CRI numbers that (allegedly) tell you that your deep orange retro-Edison bulb will make everything in your house look different than your Phillips Daylight LED bulb.