there is a philosophical distinction between the physical world and your perception
Proof?
RGB is measuring/defining proportions of different wavelengths of light
We knew about colors long before anyone knew what a "wavelength of light" is. I can tell something is red without needing to measure its photons. There are correlations between red, green, and blue, but they are not exact. Monitors do a lot of weird things with colors and so it is just false to state that there is a direct equivalence to color values and wavelengths of light that the monitor will actually emit.
I am using “internal experience” to mean the subjective way that you percieve the world.
How do I perceive the world "subjectively"? What does that even mean? Is it possible to perceive the world "objectively"?
But if you are using the word “experience” to mean “C is happening to you” then yes, the external experience is the thing that is physically happening and the internal experience is your perception of it happening to you.
So all you mean by "subjective experience" is that the things are happening to me specifically? So, if thing happens to another thing, and one of those things is a subject, then it is subjective? That is a strange way to use the word "subjective." If I eat a sandwich, is that subjective eating?