... battery needed, water power 3.Rainbow color and blue,green,red 4.Color change according to water temperature LED Shower HeadFeatures: 1. No ... flash, according to water temperature changing: A. When water temperature is ≤28°C, Blue color will show automatically;B. When ... ~43°C, Red color will show automatically;D. When water temperature is above 44°C, Red color will flash immediately; LED Shower Head