We can see only a small portion of the available electromagnetic spectrum.
We can quantify a specific color. We have a hexidecimal code system to define colors for our computers. Lowes, HomeDepot and Walmart have spectral analyzers in the paint department to match a can of paint to any color you can find.
We can all agree on names for these particular frequencies we call color. The can of red paint you buy in New Mexico will be the same color red where ever you take it.
A yellow banana in New Mexico is a yellow banana in Europe or Asia. The visual value of color does not change regardless of location, religion or cultural beliefs.
As long as our eyes have the standard cellular color receptors we all see the same colors. We all see red, blue, green, yellow and all agree that is what we are seeing - usually.
