Colored light itself is frequency in hundreds of trillions hertz or cycles per second varying within a range according to color. In music, there are several notes which also are frequency. Each note has a harmonic note in a higher or lower octave. Therefore, on the piano there are several C notes in the different octaves that are in tune with each other or cause a harmonic interaction with every other C note. Harmonics also depend on the shape of the wave itself.
Light is also in harmonics of two's and the bioenergy is enhanced also by harmonics of two's.
With this in mind, Dinshah's fundamentals of high frequency colored light could be used in lower harmonics frequencies having some of the same effect. Now you may asking why not just use color light. The problem relates to technical pollution of electromagnetic fields. In Dinshah's time there was much less interference with the light wave and its interaction with bioenergy. Also, light is just one of the three energies that make up bioenergy.