[Is there a mod to reverse engineer merged colors?]

I wouldn't need this if I was merging two colors with 255 opacity but in this case I am pretty sure one of the colors had an opacity of half or 100 or something. If a(background) + b (light effect on top, with lower opacity) = c, I have a and c, and I just need to find b at different opacity levels (they don't need to be too precise, can be 3 intervals like 70, 123, 180 or something)

[Paint.net not saving opacity in the editor]

ok it works now never mind

[Paint.net not saving opacity in the editor]

I can't create colors without them having max opacity. Even if I make a new color and put it at 100 opacity and draw. If I come back and check the opacity of the color it will be 255. This matters because I need the opacity information saved in case the background changes and I don't want light completely blocking vision of objects behind it. 

[Sprite Animation Helper (v 1.0.1.3 updated April 30, 2022)]

When I try to use it, the window defaults to a small size and when I expand it, it stays small.