It's good, well thought out.
If you haven't already, see the photos in my cory tank thread. On some of them you can see the difference in colour between the east coast sand and the silica when its all pushed next to the glass. While it isn't grey like the stones, there are beige and brownish stones in there that match the sand a bit and it's definitely darker than silica, brown like beach sand. I lightened mine with silica sand and now I'm trying to darken it again :lol: Tomorrow is sand hunting day anyway.