To see what I mean, here's a picture of the color spectrum and the size of the relative frequencies of the various colors:
In there, indigo isn't indicated, but indigo could be added... I should mention that I just noticed that I have difficulty really defining "indigo," because it's not a color I heard about much often when I was a kid. When I see indigo, I don't know how to distinguish that from blue or purple.
In the Abhidhamma's forty objects of meditation, the four forms of color meditation are:
- nila - Blue, green (sometimes I see this translated as just "blue", do they mean cyan?)
- pita - yellow
- lohita - red
- odata - white
With white, it's pretty obvious where it would be in the color spectrum (all the colors combined), but is there any objectivity to the three colors selected there? Why are these particular colors enumerated and not others, and could anyone possibly give a specific description of the color frequency (not just a vague metaphor)?
In the Buddhist flag, there is manjestha (scarlet), but it's not clear why this wouldn't be included as an object of meditation... And it's not really clear to me why they call it "scarlet," and yet it appears to be orange!
And when they say prabaswara (the mixture of nila, pita, lohita, odata, and manjestha) in the suttas, exactly what color is that?
To give you an analogy of where I'm coming from: I took a look at Eastern music theory and am similarly perplexed. All western music divides the frequencies of sound into absolute pitches, into patterns of 12 (the chromatic scale). But in certain types of music theory in the East, a scale is arbitrarily decided with a root frequency, which can be made-up entirely on spot, and everything else is developed mathematically relative to that root frequency. And also, the frequencies of sound can be divided into more than patterns of 12, meaning that notes can be separated by quarter-tones or less... And it is interesting, because I can hear the difference between one quarter-tone and another, so it's not clear why western music should divide music in this way. In fact, it's not clear why there should be 12 notes in the chromatic scale and not 13, or 14... Or why the color spectrum should be divided one way and not another way...
...And yet... when I look at the color spectrum, if I divide it in a new way, it just doesn't seem right. And if I try to play music in weird scales, outside the chromatic scale, it just sounds like noise!
But there doesn't seem to be any justification for why I can't see colors in a new way, or any justification for why music in strange scales should sound like noise.
Oh, and also: Does Abhidhamma associate colors with any particular moods or virtues? Is there any particular ground for associating colors in this way?