LED Bath Light colors water according to its temperature

Instead of dipping a dainty toe into your bath to see if it's too hot or too cold like some kind of bathwater Goldilocks, just check out what color it is. At least, that's what we'd all be doing if designer Kai Chan's LED Bath Light was in every tub. You can also set it just to display a decorative color, act as a lamp, or a candle — the candle mode has it flickering softly, just like a flame on a wick.

Sadly, it's just a concept at this time. I wonder if there will come a time when we adjust our shower and baths not by feel, but by looking at the color of the water? Or hey, how about a thermostat?