I would like to clean up the edges of a normal map within blender as it's easier to see artefacts.
Unfortunately I cannot find any information on how to actually paint blue (neutral) or any other colour as every blend mode doesn't seem to work as expected.
I'm assuming it's because the colour space is non colour but can't see any solution other than creating a new brush which would defeat the point of using blender to do this at all.
an area that could easily be painted over.
After using value blend mode, constant falloff, 100% strength using the colour of the surrounded area.