So we went with Pearl Matrix as we liked the larger pebbles...Satin Matrix is the same thing but has smaller pebbles (many claim will be softer and smoother) - Yet to be determined by us. To be honest Jamie i was really scared once they put it in as i was scared it was going to be too light. I personally really liked the midnight ocean but it was a lot darker and i was scared it would make our tempature to hot to enjoy. So they sprayed it in and i instantly regretted not going with the Midnight Ocean....It was to pastel...Then they came and did the acid wash and i thought ok that looks better....then it started to fill with water and i saw the sparkly abalone shells and thought oh this is going to turn out beautiful. Last night the water was dark enough for my taste...cant wait to watch it all day today and see how the sun makes it sparkle.