Interesting visualization, but I don't understand it.

I went to Ede, Gelderland (where I live), and while the city itself is mostly blue, the Hoge Veluwe just NE of the city is suddenly yellow (or is it green? I'm color blind), indicating that it's ~45m above sea level. That can't be right, the Hoge Veluwe is on the same level as Ede. What am I misreading?

Edit: I think I understand what's happening: the land immediately east and north of Ede is forest, so I guess the increased elevation in the point cloud is trees.