I agree with you that colors are fascinating philosophically. Besides the things you mentioned… there is that thing about them… that they are so simple, and yet so concrete.

This sounds like great explanation to me.

I really like the whole color thing since it can be used as great example when you are talking about sign, reference, perception and meaning, and how really important reference is to knowledge, and everyday speech.

The analogy would be with Jane seeing just the form of the ball (e.g. oval), and John seeing the size (e.g. 30cm). I guess nothing is problematic in the case, and we can say that the ball is both as Jane and as John sees it.

As long there is no contradiction in two predicates, there is no problem. So, what I say, is that both “true blue” by John, and “slightly greenish blue” by Jane are two aspects of the objective color, in the way that ‘oval’ and ‘30 cm radius’ are aspects of the ball.

They are not contradictory in this picture, as John’s “true blue” is incompatible as predicate with *John’s* “slightly greenish blue”. But, as John and Jane pick out slightly different aspect (through not orthogonally different), it is not incompatible with Jane’s “slightly greenish blue”.

In fact, neither John can experience exactly the same hue that Jane experiences, nor she can experience exactly the aspect John experiences. So, it is NOT the problem “I can’t imagine a color that is both slightly greenish, and also not greenish at all”. That is true, in case if we are limited to the aspect of one person. But here we have two aspects, and “true” in “true blue”, and “slightly greenish” in “slightly greenish blue” are relative to the aspect.

You say that you ar etrying to defend option (a) which says that the object is both blue and blueish green at the same time, but it looks to me like what you are actually trying to defend is option (c) which say that the object is some other color than the ones that Jane and John experience. What else could it mean to say that they are both just seeing one aspect of teh (real)color if not to say that the actual color of the chip differs from each experience. You can’t really be saying that in reality the chip is both blue and not blue?????

But I have another question.

After what you have said are you referring to the biology of the human eye? If not then what is the factor you are are refering too?

No, “true blue” would be relative to which aspect of the objective color the individual’s color space pick out. That is, John and Jane would have different “true blue” color. I guess I should have explained more the picture, On it, only the “true blue” color of John is represented as a point(blue circle) in John’s line, a point which is an aspect of the Munsell chip 527. Different aspect of that chip is picked out by Jane, and is represented by slightly greenish blue on her line. The “true blue” point for Jane is not represented on the picture, but it would be solely on Jane’s line, same as John’s “true blue” is on his.

The picture isn’t supposed to represent the relation exactly, just to give the idea of what is proposed.

Would it be true that where the greenish blue and true blue lines meet that that is where the true hue of blue would be?