Real Madrid CF = White
Club Atlético de Madrid = Red and white vertical striped shirts
FC Barcelona = Red and blue
FC Bayern München = Red
Juventus = Black and white stripes
Sevilla FC = White
Paris Saint-Germain = Blue with a red central and vertical band
Borussia Dortmund = Yellow and black...
All those theories about it being seen as more aggressive and so on, yet no mention that red may just catch the eye more easily as it's less commonly found in nature so it draws the eye to it and you notice it sooner. (football teams, etc... would benefit as team mates could spot their team...