Sycamore Variation?

I remember asking my dad years ago about this and he didn't know (not that I expected him to, his ideal garden is a concrete driveway:( ) and the other day I noticed it again and it reminded me that I'd been meaning to ask so

why does this sycamore have large leaves with purple undersides:



the leaves are also very large

and why does this one have green undersides:



and smaller leaves


The pictures are of different trees and none of the trees showed both purple and green leaves..


is it just natural variation or is the purple a hybrid?

 

Looks like I might of found the answer myself....

it's the cultivar Acer pseudoplatanus 'Atropurpureum'

 

I just found this post. I have this tree in my garden. I planted it over twenty years ago. I was assured it had good autumn colouring. It hasn't but the leaves look very pretty in the wind as they show the different colours. A nice addition to the garden I think.