@futurebirdmyrmepropagandist right, if we’re talking like prime numbers, colors do not really exist out in reality. What we have is wavelengths of light with wavelengths between 400 and 700nm, what we call the “visible spectrum”, and cells that have “response curves”, the lines here represent how much each type of cell is stimulated by each wavelength of light in the continuum

we end up with “primaries” because the whole range of wavelengths under the curve all creates the same signal in our visual plane- so we can simulate the perception of all the wavelengths using only a few, in proportions. level of stimulus; S, M and L are as close to “real” primaries