just lie about the led itself as that is the costly component. Who is gonna measure wavelengths and hold them accountable? its a no brainer move to scam the most expensive component that also is hard to verify
Are LED's particularly costly though? Does one wavelength of red LED differ significantly in price from another wavelength of red LED? And does that even matter that much? It seems like higher wavelength has deeper penetration, but how deep you want depends on use case.