You want something with high opacity if you're changing to a light colour. I would probably sand that first to get rid of the texture, then Dulux Trade Diamond Emulsion, if you have a problem with the copper flake staining the paint then try zinsser 123 or cover stain to seal it.
Went with dulux trade matte as I had some lying around. It’s covered the non glittery walls in two coats no issues but completely refused to adhere to the glitter wall despite it being sanded first 🙄
Got some zinsser bin so will do a coat or two of that instead.
5 years ago, we decided super dark blue with copper glitter in it was a good idea for paint in the downstairs bathroom. It was not.
What’s best to prime it with? Zinsser 123?
Calling @Airhead