When I describe Ouagadougou to people I call it a brown city. There is dirt and dust everywhere. It is mostly due to the fact that this is harmattan and Ouaga gets you farther north, close to the Sahara. However, it is also because most of the buildings are made from mud bricks instead of cement.
I took this photo from the airplane as I was flying into Ouaga from Abidjan. As you can see, everything looks brown – almost like I added a sepia effect.