When I got my hair done this last time my stylist asked me if I was using purple shampoo. I had NO idea what she was talking about and she told me to just go to a beauty store like Ulta and get purple shampoo because it would help to my hair keep the platinum rather than going yellow.
I took her word for it and walked into the store. "Uh, I need purple shampoo...?" I felt so silly but the sales associate simply smiled and walked me right over to the shampoo. I grabbed a bottle and felt happy that I had accomplished the task.
It wasn't until I actually used it that I decided that having this hair color ROCKS!! I get to use the coolest shampoo!! I didn't realize they meant it was actually PURPLE!!! (And it smells good too!)
(Not sure where this photo came from, do you?)