Water Glow Faucet Light Finally, Color-Coded Water! It's always bothered us that hot water and cold water were the same boring transparent color. If you feel the same, here's a faucet attachment that makes water above 104F glow red and water below 104F glow blue. It's powered by (3) button-cell batteries (included and replaceable) and has attachments to fit the (3) most common kitchen and bath faucet sizes. Measures 2-5/8" long x 1-5/8" dia. Works by magic.