My YWG was very yellow when it was little, it's changed some as it's grown getting lighter and darker again now that it's an adult. I don't think having the pistol shrimp had any affect but they are fun to watch. The main thing I think with having a pistol shrimp is making peace with your tank becoming what your shrimp wants and not what you want. Your scape will be the ever-changing home of your pistol shrimp. It will eventually take sand from every corner of your tank. More so if your sand bed is like mine and not particularly deep. I really don't mind though, it turns the sand like nothing else. It made what I initially created in there look more natural than I ever could. Occasionally I have to put things back that it incorporated into it's latest build. Sometimes I need to unbury a coral. When it abandons a section of it's expansive house I'll redistribute some of the sand back to areas it has left a little naked. It's a very busy little bee, quite the bulldozer and builder. I've never had an issue with water clarity though, might be a difference in sand size. Mine is a bit coarse.