The lights glow different colors based on the current water conditions. Blue lights mean the water is safe for swimming, while pink lights mean that pathogen levels have risen to unsafe numbers. Additionally, the lights change in "brightness, frequency, and sharpness," based on oxygen levels, turbidity, and pH.
Besides the floating sculpture, they are also collecting real-time data on the water conditions in an online dashboard.
Maybe something we need to see more of permanently around the world. IT would certainly make citizens more aware as many do not go visit online dashboards.
There's more to the lights than meets the eye.