To neutralize colors, add the complementary color.
Cyan – Red
Magenta – Green
Yellow – Blue
So for a greenish photo, you can try a magenta gel over the flash or color-correction filter over the lens. Fluorescent lights are historically greenish, so an F-DL filter might do what you need. (They're often included in cheap filter kits, so you might have one ...
Several parts here.
The most important part is planning. It is pretty obvious that it will be very hard to adjust two photos in very different lighting situations, one on a sunny day, and another in the sunset.
You probably have a misconception about the color profile. That is as simple as assigning it to both photos, but it does not tell anything amount ...