We went ahead and used very dark blue 1" tile with black grout for the spa, beach area, and pool tile line. The pool was done in Wet Edge Black Magic pebble finish with Abalone added. The pebbles were black, brown, white pebbles and blue quartz with black plaster and Abalone sprinkled on the top using a fertilizer spreader.
I do not know how to add a picture or I would include it here.
You can view a sample of the Black Magic pebble finish on YouTube by searching for Wet Edge and Black Magic.