The 'Red, Green and Blue Increase/Reduce' parameters are the most important settings in the Color module. They directly determine the colour balance in your image. Their operation is intuitive; is there too much red in your image? Then increase the 'Red Bias Reduce' value. Too little red in your image? Reduce the 'Red Bias Reduce' value.
If you would rather operate on these values in terms of Bias Increase, then simply switch the 'Bias Slider Mode' setting to 'Sliders Increase Color Bias'. The values are now represented in terms of relative increases, rather than decreases. Switching between these two modes you can see that, for example, a Red Bias Reduce of 8.00 is the same as a Green and Blue Bias Increase of 8.00. This should make intuitive sense; a relative decrease of red makes blue and green more prevalent and vice versa.
Nevertheless the result can look quite pleasing when simply browsing past the image in a Facebook feed.
In other words, dynamic range of the entire image is not adjusted to accommodate the reconstructed detail.
StarTools enables you to keep M42's colour constant throughout, even in its bright core.
Again we then know we should adjust red or green accordingly.
You can convert everything you see to a format you find convenient. Give it a try!