Grey bars when watching video that doesn't match screen size when "use limited color range" setting is disabled

The proper setting for you is likely to be running in limited range, as it would be for most people outputting to a TV. It would be highly unlikely the 4:3 video’s your playing where mastered full range anyway so even if you were able to get this working there would be no extra color information there to be gained. This setting does not affect HDR. If you really want to run it this way you may be able to use a whitelist to output to 4:3 content in 4:3 so the bars are generated by your TV instead of Kodi. You can find more information about them here…