The bottom photo shows the lower roof of the Cdn War Museum green roof. The grass is green. Further up the slope, beyond the admin offices with the gorgeous views of the River, the green roof is decidedly brown.
There is a N/S bicycle and foot path up the centre point of the museum which takes you to the roof and down the other side. The views are interesting. The path is supposedly open whenever the museum is open (there is a locked gate other times) but I often see it locked mid-day. If you are lucky and see it open, ride up and enjoy the view and unique windblown grass roofscape.