Hello... :)
Not sure what you want covered?
As to the old days and old sensors (see affordable) most had poor resolution in the blue and red end of the spectrum.
Many cut off completely before 660nm red (important to plants)
Also some over sampled in the green region.
Under in blue over in green it sort of averaged out for "normal" types of light especially true black body types (sun and tungsten filaments types) but not for leds with its blue spike.
And to sort of add to the above it is used mostly as a comparator. What is your light today vs last year sort of thing.
Parwise has a big sis that does 1nm increments. Parwise is 5nm..
https://spectra.seneye.com/