Why Does Kenpo Not Use Kung Fu Sashes?

I was told Kenpo comes from the Chinese martial arts. So I was wondering why they do not use Kung Fu Sashes instead of karate belts?

My only observation or answer would be that karate belts are easier to use and buy. Especially back in the early days of the martial arts in the USA. Where would they go to get a genuine sash in the 70's?

Also the karate uniforms were a bit easier to wash and wear. As the kung fu uniform would rip easier.  So there you have it - the reason why Kenpo does not wear the Gunf Fu Sash!