Thanks Rick, better communicator than I. ADU means Angels Dance Upwards to me
(from Enigma). No matter where you look in this game there are terms and acronyms everywhere that are hard for laymen to understand. I simplify for myself to better comprehend what changing something will result in for my final picture down the line and what to "look" for along the way in my work flow.
I don't know what effect the filter makes, can you try without it and see if your red dominance is still there. Levels adjusting each colour channel individually not as a single RGB adjustment is a simple photoshop trick for colour restoring faded/colour cast photos. It worked for my early Jupiter shots where the camera software was auto white balancing and couldnt be controlled so giving weird colour casts each time.