Sitting looking at the various shades of green leaves in the trees next to where I live I realised there are no blue leaves.When I was at school I was taught that there are three primary colours: red, blue, yellow. All other colours come from a mix of these, plus black and white, which are not colours.
So for there to be leaves that are green (green is a mix of blue and yellow) there should probably be yellow leaves and blue leaves too.
There are yellow leaves. But there are no blue leaves. So perhaps the old ‘primary colour’ rule is wrong. Perhaps green is not a mixture of blue and yellow after all.
A possibility that I find bracing.