Paint the color/material of non-visible interior area
I have a print I'm working on. There are two very small areas in layer 18 that are not visible in the finished product. As in, I can't even paint it from the model view because it's buried inside a layer that is otherwise 1 other color. For some reason, the slicer handles this with 3 tool changes, 1, 2, 1 again for a few small spots before moving onto the next layer and the correct tool for that layer. It doesn't even finish all of tool 1 before changing for tool 2.
I think I can solve the problem if I could just paint these areas to force them to use tool 1, which the entire layer should be using tool 1 anyway. It would then move to tool 2 for the next layer.
How can I reach this area with the material painter? Attached pic for reference. The rest of the offwhite is infill to account for those two otherwise invisible areas.