Hello - We are starting the installation of our pool and are looking for a dark slate colored glass tile that will be durable here in Portland, Oregon, where occasionally temps fall below freezing. I am looking for something like this pool in Magnetite Fireclay tile, but it is only frost-resistant and even Fireclay suggests using one of their glass tiles. Any recommendations for matte glass tiles in this shade of slate gray? We are thinking of doing Maui Black Hydrazzo for the pool surface if that is helpful. Thank you!