To elaborate on why the RGB color model is convenient for representing color...
The choices of RGB in trichromatic reproduction systems are such that the individual contribution of each minimizes the cross-cone activation in the eye, allowing greater fidelity (widest gamut) in color reproduction with only three sensors at input and three emissive colors at output. In other words, if you're going to use analog electronics and passive filters, it helps to make the selected primary frequencies as functionally orthogonal and isolated as possible.
Consider the quality of an absorptive filter and/or response profile of a pixel on CMOS sensor; so long as a it has a strong peak at the primary frequency, then we're not too concerned about leakage from other frequencies into it; nor are we too concerned that nearby colors could leak a little into the other two channels because this will mostly be correlated with overall luminance, which makes it very hard for the eye to discern upon reproduction (it looks a little more washed out).
This is why Young and Helmholtz initially identified red, green and blue as primary colors way back in the early 19th century. They tried to identify three specific color frequencies that could be used to mimic other pure frequencies through re-combination in test subjects, based on a theory about how the eyes worked.
While these colors do not correspond to sensory peaks for each cone cell type, it turns out the retina/visual cortex's post processing (the "opponent-process" discovered by Ewald Hering) derives hue from the combined activation ratios, and is thus bypassed by using combinations of RGB to create hues as opposed to direct spectral activation.
The choices of RGB in trichromatic reproduction systems are such that the individual contribution of each minimizes the cross-cone activation in the eye, allowing greater fidelity (widest gamut) in color reproduction with only three sensors at input and three emissive colors at output. In other words, if you're going to use analog electronics and passive filters, it helps to make the selected primary frequencies as functionally orthogonal and isolated as possible.
Consider the quality of an absorptive filter and/or response profile of a pixel on CMOS sensor; so long as a it has a strong peak at the primary frequency, then we're not too concerned about leakage from other frequencies into it; nor are we too concerned that nearby colors could leak a little into the other two channels because this will mostly be correlated with overall luminance, which makes it very hard for the eye to discern upon reproduction (it looks a little more washed out).
This is why Young and Helmholtz initially identified red, green and blue as primary colors way back in the early 19th century. They tried to identify three specific color frequencies that could be used to mimic other pure frequencies through re-combination in test subjects, based on a theory about how the eyes worked. While these colors do not correspond to sensory peaks for each cone cell type, it turns out the retina/visual cortex's post processing (the "opponent-process" discovered by Ewald Hering) derives hue from the combined activation ratios, and is thus bypassed by using combinations of RGB to create hues as opposed to direct spectral activation.