All the leaves are brownnnnn.
And the sky-yy is greyyyy.
I've been for a walk...
Something about the surface texture of bus & cycle lanes seems to trap the leaves so that they stay there for weeks, making all these pretty patterns.
The regular tarmac of the road doesn't trap them.
Lordy it's a mystery. Somebody give Derek Acorah, Arthur C Clarke & the Amazing Randi a ring, I demand answers.