Is this a trick question? Are we talking about the physical colour of the wind or is this a rhetorical question which requires no real answer, just a discussion?
I think this question simply states that there are many questions in life we ask ourselves, but we just can’t seem to answer them. Questions about the future, our past experience and why it happened, questions about our religion or about death, about the beginning of life and the missing link, big foot, the abominable snowman and the great sea monster, why some people have to be such assholes or why we never get to do ‘this’ or ‘that’ ,to name a few. We can’t answer these questions because we don’t know the answer or we are not always right about it.
It is great to ask questions to gain more knowledge, but sometimes you must work with what you’ve got and stop worrying about what might and might not be.
If the wind really did have a colour for man to see with their own eyes, perhaps the colours of the rainbow would have been something beautiful to see floating by.