Hi all. I’m having some lovely light grey coloured paving stones laid. They are heritage sandstone. I’m slightly concerned as the installer says he will need to seal them when done and it will make the colour darker like when it rains. Well - I don’t want them darker hence why I picked that colour!! Does anyone know of a sealant which won’t make the stones darker but will give some protection against moss etc. I’m slightly freaking as the paving was very expensive and I spent ages debating colour choices. I love the colour it is now! Thanks.