Trees with pastel bark?

While in London this month, I noticed trees with a strange pastel pattern on their bark. I’ve never seen trees like this in Canada, and I’d like to know what sort of trees they are, exactly. They almost look like they’ve been painted! I saw them in other European cities as well.

Can anyone help me out?

It looks like a Sycamore.
Here’s another, and one more.

That looks about right, thanks!

Very close. Trees in London are likely to be what are called London Plane Trees," Platanus acerifolia, which is generally considered to be a hybrid between the American Sycamore Platanus occidentalis and the Oriental Plane Tree Platanus orientalis. The trunks look much the same, but the trees differ in their seed clusters and leaves. London Plane trees are commonly planted in urban areas in the US, while the American Sycamore is common in eastern forests.