Maybe we should illustrate this with numbers. When you change the speed of light, you automatically change what wavelenght a specific source sends out.
It follows a very simple formula. wavelenght = speed of light / frequency
For example, if we start with a lamp that sends out light at a constant frequency of 6.6*10^14ish Hertz.
Normally, this corresponds to light with a wavelengt of 300000000/(6.6*10^14) = 454 nanometer. This is a rather nice deep blue light.
If we suddenly increase the speed of light by even, say +50%, we get.
A new light with a new wavelenght of 450000000/(6.6*10^14) = 682 nanometer. This is a rather nice bright red light.
So the same source starts producing light with a different wavelenght. Note that the light already produced can't change it's wavelenght in mid-flight because that would require serious screwups both in energy conservation and the location of the beam.
It would be required that the spiritual stars were made up of different atoms in order to give off a different frequency, and then somehow change into normal atoms during the shift. Unless you have a testable model for such radical changes, I suggest you drop it.