Modern phones have some amazing processing of the data from their cameras. For example, the raw image below of a sculpture in a park after sunset (demosaiced using IGV method in RawTherapee and developed in the "Neutral" profile) has some colorful noise, which is totally colorless in the JPEG shot of the same scene with the same parameters (shots done using RAW+JPEG mode in OpenCamera). The photos were taken using Samsung Galaxy A320F/DS at aperture f/1.9, shutter 1/16s and ISO 2149. I've also seen similar processing in the Raspberry Pi camera V2.1 (Sony IMX219), and many of the modern DSLRs appear to also lack any colorful noise in their JPEGs, still having colorless noise.
I wonder, what algorithms are used to achieve such conversion of colorful noise to colorless one? Is it some high-ISO-optimized demosaicing? Or is it a special denoising algorithm applied after demosaicing? Or something else?