I have a main scene, and all other scenes in the game are instanced under it sequentially. It has multiple theming options, and I need the black bars to be consistent with the theme that is selected. It only needs to be a flat colour, but I couldn't find a way to simply change their colour, so I used this:
VisualServer.black_bars_set_images(texRID, texRID, texRID, texRID)
This gets the RID from a 2x2 pixel png with the colour it needs. The problem is, whenever there is a change of scene, the black bars flash white, and I'm not sure why. If I disable this line, the black bars are there, and do not flash, and generally just behave as black bars would normally behave. How can I get rid of this white flashing? And is there a better way to simply change their colour, rather than using this workaround?