There was a great public danger in the USA that unqualified therapists were using colour healing as an unorthodox medical cult. They might well produce cures where the illness was psychosomatic, but cures were unlikely where there was serious physiological disease. The American government had to deal with the relatives of many patients who died under colour therapy and published propaganda films that outlawed it.

One of the greatest quacks of all time was Colonel Ghadiali, who treated people with coloured lights for thirty years and made big business out of it. He was arrested in 1925 and spend five years in Atlanta Penitentiary. During his trial, he had no trouble in finding 112 witnesses testifying that they had been miraculously healed by coloured lights. One witness, an epilectic, had a fit in the courtroom just after shouting 'I tell you I had fits all my life until Doctor Ghadiali cured me !'