Proenza Schouler started a whole colored hair craze with their SS 2010 collection where the models walked down the runway with colored hair tips. Ever since colored hair has been popping up in editorals in various magazines.
The wonderful pictures of Rasa (♥) above inspired me so much that I acutally bought one of these cheap colored hairsprays >.< haha. I can't wait to try it out altough I doubt it will work that well on my medium length hair, we'll see!
Also those color code Swatches look pretty neat. I love the light blue and the pink one.