The pattern of this roof looks like the corn.  I guess they are ceramic roof tiles which had changed their colours over a long period of time.  Some of them may had been replaced by the house owner with the new roof tiles that’s why we can see the different colours for each tile where if we see them as a whole thing, it creates a corn seeds pattern. 

Some of their colour are lighter, some of them are darker, some are white colour, some reddish, and some of them are brown or black.  The darker colours roof tiles are actually the colours of the moss on it I believe.

The roof is very old already.  Do you notice that some of them are missing?

Actually they are many other things which is not nature by default, because it is human-made, but if we look carefully, it actually show its nature behavior or slowly changes its behaviour to adapt to the nature environment.

Who say human-made stuffs doesn’t look nature?  Tell me who says?  Who says?  … …  [This sounds similar to an advertisement on tv.]

From my point of view, human-made stuffs are also parts of the nature, because human itself is parts of the nature.  The only things that make the difference is that either the stuffs can make the nature become more nature or otherwise destroy it.