Everyone’s eyes/brain interpret colors by taking signals from the 3 types of cone cell detectors and combining them into 2 color-difference signals (red–green and blue–yellow) and 1 brightness signal. The latter of these has the best spatial/temporal resolution and is used for interpreting textures/fine details, edges of shapes, motion, depth, etc.
In a sense, everyone’s vision is primarily grayscale, with lower-resolution color information layered over the top.
And then you have to take into account that our sensitivity to some colors then others. Our cones are tuned to what can be approximated as three different bands of wavelength, which are centered in and sufficiently overlap around the green wavelength to result in our being most able to discern the color. Human eyes can discern at least twice as many distinct shades of green than they can red or blue in a uniform distribution, and color science has to take that into account to prevent such an image from appearing overwhelmingly green.
Everyone’s eyes/brain interpret colors by taking signals from the 3 types of cone cell detectors and combining them into 2 color-difference signals (red–green and blue–yellow) and 1 brightness signal. The latter of these has the best spatial/temporal resolution and is used for interpreting textures/fine details, edges of shapes, motion, depth, etc.
In a sense, everyone’s vision is primarily grayscale, with lower-resolution color information layered over the top.