Mirrors are able to reflect light but are not perfect and after a number of reflections, light loses intensity.
However I wonder, during the reflection by a different type of mirror, could the light photons lose some energy and thus be red shifted instead of just losing intensity?
I am not talking about light becoming more red, as a simple color filter on top of a mirror could do, but rather e.g. blue becoming green and green becomes red, etc.
Does such a mirror exist?
Also I am not looking for a digital system with a camera and screen. I am looking for physical processes that would shift light frequency.
It would seem there is no natural pitch shifter for acoustics too (swallowing helium gas is not pitch shifting an existing sound).
Addendum: I am looking for a static device, not a moving mirror.
Very simplistic simulation of how you would look like in such a mirror, assuming you are a brunette wearing a red top.
Left picture is the original. Middle is shifted: blue becomes green, green becomes red, red is invisible (black). Right: one bigger shift, blue is now red and the rest is gone to infrared.
This is just an illustration (or even dramatization, given the amount of shift), don't take it too literally in terms of redshifts I am interested in. Also this assumes there is no UV or higher energy photons in the original scene that would become visible after being shifted.