PixInsight SpectrophotometricColorCalibration process (SPCC)
The new PixInsight SPCC process is well worth looking into.
It uses the latest Gaia satellite data from ESA to calibrate the colour in your RGB images. Gaia was launched in December 2013 and SPCC uses the 3rd release of data made available in June 2022.
Check out the following better YouTube videos:
Adam Block (part 1 & part 2)
You will also need to download from the PixInsight software distribution site the Gaia DR3/SP data (I use the 'Complete Set' which is about 63GBytes)