save water / faucet

So this machine will make water color change when you reach the time preset with the timer.
The machine shoots lasers, which will reflect in the water spout when the time is up.
When the lasers are reflected, the water color appears to be changed.
Then, the user knows how long he or she uses water, upon seeing the water color change.
The color change is to arouse the user's attention to saving water.