What is the colour of a leaf?
I'm sure many of you immediately thought of green.
What if i told you that a green leaf is actually any other colour but green?
You would probably call me crazy.
Now lets go back to basic science. White light is made up of 7 basic colours(violet,indigo,blue,green,yellow,orange and red). We know this because when we pass white light through a prism it splits back into these colours.
Any given object absorbs some wavelengths of light and reflect the rest. So what we see is actually the sum of colours that did NOT get absorbed by the object.
In other words a green leaf is any colour but green. We perceive it as green because green is the colour that gets deflected the most from a leaf