We just gave you a recap of Paris Fashion Week face trends, and now it's time for the hair. With side parts and updos, Paris runway hair "is where we step out a bit more and really push the envelope," says Guido, the Redken Creative Consultant (and Interview subject) who is responsible for taming the tresses at YSL, Balenciaga, Lanvin, Nina Ricci, among others. Guido continues: "This Spring/Summer 2012 season was more about natural beauty, which we saw reinvented in modern ways.  Each city (New York, Milan, and Paris) has a different personality—in New York we generally see more natural and sporty hair; in Milan, it is very rich feeling."

Click through the above slideshow for Guido's top trends and the runways that flaunted them.