I know this has been talked about before. I just ran into a old pic of my ss motoro I got a few years ago. when I got her she was a light base 2 year old ray now she is a dark base color. I know people use light sand to try to get a light base I have had her on pool filter sand mix with black sand and a lg grade natural sand now bare bottom and very dark. it seems she has been dark really shortly after I got her. just woundering what others have experienced.