The best type of paint for bathroom walls and ceilings is semi-gloss paint. It's recommend by painting pros because it handles moisture better than flat paint and it can also be cleaned.
Paint that is formulated for the bathroom space is generally designed to hold up well to frequent cleaning and washing without losing any of its beauty. Bathroom paints are resistant to stains and mildew. Bathroom ceilings should always be primed prior to adding a layer of paint as priming seals the surface and helps the paint adhere more efficiently. This also reduces the risk of mold formation within the walls.