No, I'm not talking about doing your wash. I am referring to the purpose of understanding how Music and Color relate to each other.
Have you ever heard a tune which just sounds "sappy happy"- not genuinely uplifting like some of the spirituals and psalms, but sappy sweet?
How about one that just sounds morose with no real meaning?
Part of that "yuck" factor is the lack of color shading in the tune. If you look at some of the great 'color field' painters of the past generation, Mark Rothko, Clifford Styhl etc. notice how even within their large field of color there are differentiations;
Yellows are not simply one yellow, Blues not just a single blue etc.
Otherwise you might as well just ask Sherwin Williams or Dupont to create your next masterpiece.
In music the same principle exists. Using the same color creates monotony-monotones do not give the listener anything to hope for. If its all happy flavors we are just bored to tears, even more so than just sad flavors. Unfortunately we have way too much of this type of music.
Good art must effectively utilize and contrast/combine lights and darks to make pieces that genuinely reflect emotions.
Emotions which are not simply happy or sad but actually contain dimensions greater than 2, just like me and hopefully you.