Some purple students at a Waterloo Engineering event (from engsoc.uwaterloo.ca)
Waterloo’s official colours are black, gold and white, but you might have noticed that Engineering’s brochures, websites and other material have a lot of purple. Sometimes I’ve been asked why that is, or why we are using Wilfrid Laurier or Western University‘s colours. The main explanation is that sometimes our students are purple, as illustrated in the picture, so why not use that as our theme colour? But there are purple engineering students at other universities like Queen’s, so there is more too it than just that. There is a bit of a long explanation that can be given in more detail as follows.
A Professor in Waterloo Engineering 