root42 on Nostr: Could be! But that's what I meant: the dots are the color signal. If it creeps into ...

Could be! But that's what I meant: the dots are the color signal. If it creeps into the luma you get exactly this. You can try plugging in only the luma + sync signal if possible. That should give a monochrome picture with the same dots IF it is the chroma seeping in. If the picture becomes clear it's the chroma signal on its own. You might also look for mods to make the picture better. Maybe the community has developed some. Which board ASSY do you have?