It's amazing what some tastefully applied colour can do for a building. If all the glass was clear, I doubt anyone would take notice of this building beyond Brussels. The same goes for Montreal's convention centre, where a simple modern facade with a mosaic of vibrantly coloured glass allows it to make the covers of tourist guide books.
It may seem shallow, but the right colours can make a building a lot more eye catching and may keep opinions positive even when its style becomes out of fashion. A combination of colours on a neutral background is a safe bet, because a single unusual colour can be very polarizing.