We got our pool remodeled and we choose a dark grey grout color. After it was finished everything looked great but after a little less then a month the grout changed from grey to white. Im not sure if it’s efflorescence as I’ve cleaned it with Muratic acid and it probably made it more white. When wet the color gets darker. I’m not sure if this is something that just happens or if the builder messed up. ive talked to the builder and he said it’s probably just efflorescence and just needs to be cleaned but I’ve tried that nothing works. I really want to figure out what the problem is