Erase color from image in GIMP – Graphic Design Stack Exchange

Now I want to remove “something” (some color) via “some tool” from the whole image in layer1 (not just the background or some specific parts), so that the result of this action, put on top of the solid color layer2 and viewed together with it look like the original image. Is this achievable (preferable in GIMP) and how?

 https://graphicdesign.stackexchange.com/questions/154249/erase-color-from-image-in-gimp