Hmmm, I wish I could agree, but from what I have seen, everybody inside a dojo knows pretty much exactly what kyu rank the other deshi are anyway - coloured belts or not. It sounds like a good idea because it seems that having only white belts would get rid of the competition between people. But I think that (if I like it or not) competition is part of human nature and therefore it only covers the "problem". It is great at seminars though, where people do not know each other.

In our organisation we have dan ranks for teenagers up to 18 (errrr.... years old I should add, not 18 dan ranks ). They don´t have to do the theoretical part of the test, but have to do that as soon as they turn 18 or they loose the rank. Alternately they can do the three week´s course/certificate for teaching aikido when they turn 18.