The use of colour is modern, bold, and graphic. It adds some interest and life to the building.
It emphasizes the alternating angles of the balconies. Yes, the wedge shaped balconies reduces the functionality of the balconies and not very furniture friendly, but in reality most don't really use them other than to smoke or enjoy a drink while taking in the views. I don't live there so it doesn't matter, but at least it looks neat and respectable on the outside.
Just compare it to the Studio Condos in the background, where it's the typical huge mass of grey window wall with grey spandrel -- not very inspiring.