Would that matter if the information weren't encoded using the wavelength? Eg, imagine that they toggle the light very quickly, Morse-code style, to encode mess

Would that matter if the information weren't encoded using the wavelength? Eg, imagine that they toggle the light very quickly, Morse-code style, to encode messages. If the frequency changes slightly, no big deal. EDIT: I suppose this effect could make the speed of the toggling appear faster or slower, but that could be adjusted for.