I am trying to create a map of a building in GIMP . The building is color coded by section with 30% opacity, and the space between the colors is currently white because that is the color of the base image that everything is being built onto.
The layer that is to have the walkway colors was put next to last in the order. It is just a transparent layer. I put it near the bottom of the layer order in effort to use a paint tool to color over the other layers and only paint the Alpha channels without painting any of the department colors. I remember being able to lock upper layers to do this. Every time I've tried, I have locked the pixels, position, and alpha in different combinations. Whenever I've started to paint over the white it paints everywhere. What am I doing wrong?