post processing: is there any way to use black and white conversion to reduce noise?

My understanding of noise is that it is, in effect, because the photos are not distributed evenly over time. So, if you are filming in low light conditions, you will get more noise because there are not enough photons to "average".

My question is this: I think there should be an algorithmic way by which you can sacrifice the color information (perhaps going back to the test phase) of a RAW file to eliminate the noise. this blue did not capture as much light, so it is probably an error in this image (white balance).

Is there such an algorithm?