I've only come across this just now and I really like the idea. Especially the idea to teach this in schools.
Not sure how applicable it is to management (other than that we could all benefit from less complaints), on the other hand I can imagine that you can make fun team excercises related to this. Everyone in my team used to know that they can't come complaining to me unless they also have to offer a suggestion for a solution.
Maybe this is big in the U.S., but personally, I have never seen anyone with a purple bracelet around here :)
Was just wondering if anyone happens to have read the book and can comment on it?