Is "Recorder Karate" culturally insensitive?

[Spartacus Maximus]

The idea itself is not a bad one or a new one. As others here have said, karate borrowed the idea from Judo and the founder of judo was himself inspired by rank or level markers used by athletes or school students. Swimmers, if my memory is good.

Even nowadays Japanese schools use different colour uniforms for each grade or level. If some teacher somewhere wants to use a similar system for music or whatever else, it will work just as well to motivate young learners.

If an idea is useful and works well when applied in practise, who cares where it came from or who thought of it first and where that person may have been from?