hi I'm wondering if anyone can help, myself and my work mate recently rough casted a house in Tudor chips. After it was finished the chips dryed in 2 different shades of black, some black is really vibrant and some black is very dull and dusty almost like a patch work quilt, when we wet the wall the dusty/dull chip looks fine and it all matches but when it's dry it goes back to looking different, we have tried coating the wall in an acid based solution but this has no effect. Any advice would be well appreciated.