The messenger.

If we are shown a green leaf and asked what its colour is, we will reply that it is green. However, it is not green. It only appears to be green because it absorbs all but that part of the light spectrum that makes green, and that is the part that is reflected to our eyes. A beautiful butterfly wing is not beautiful at all; it only looks that way because the tiny scales on the wings are angled in different ways to create different colours.

Above is an extract from The Milk Is White [Chapter 8, page 37, The Illusion – 2, See Note.]

Today I had a neoption in which I saw exactly how the illusion of colour is created and it is interesting that, if I let the mind get active while I was seeing this, what I was seeing disappeared. The mind intruded once and I had to remove it to regain the picture.

I saw that both the object – in this case a leaf – and the light hitting it are essentially energy in vibration at different levels. These are called wavelengths.
White light is composed light of the colours of the spectrum combined, and each colour is energy vibrating at a different level or wavelength.
Likewise, the various parts of the leaf are energy vibrating at different levels or wavelengths according to the density of the part. There is no colour of which we are aware.
[Up to this point I was covering what I already knew.]
To help understand what happens just imagine all these wavelengths as bits of string in uniform squiggles of differing undulations. Some are in the light and the others are in the leaf.
When those from the light hit those from the leaf those of the leaf get entangled with some of those of the light whilst the remaining light threads bounce off the leaf toward where the came from. These that bounce back are of the wavelengths that give us the colour/s of the leaf.
When we are told that the leaf absorbs some of the light and reflects that which makes green (blue and yellow) we now know what actually happens.
Note: For autumn colours or blemishes the principle is the same.