Hi there, I painted all the gloss in my house a couple of years ago with Leyland Trade Satinwood in Brilliant White, it all still looks great apart from the downstairs loo that has gone yellow. I now realise this is because there is no window in there so it gets no natural light at all. Am I able to use a waterbased gloss over the top after a bit of a rub down or will I need to make extra preparations? Also any recommendations for a suitable gloss that won't go yellow would be appreciated. I prefer a Satin finish to a Matt or full Gloss. Thanks.