Here's a simple image I took from pixabay, in a video about compositing, (I'm using blender's compositor here, but the general principle should apply), the author said, "in this image, there's more tinge of yellow, so to get rid of more yellow , we increase the saturation (Hue was yellow-ish) of this white level"
Which is basically increasing the amount of yellow: This is my example of how it was done, since I cannot include the author's original tut's image:
But, I'm not quite understanding this principle and how does this analogy apply for the black level i.e. What if we set the RGB value for the Black level to be something yellow, how does it alter the image? (I mean I could see it in the compositor but I'd like to know the theory)