Colour changing paint

[TransAmDan]

Just came across this. looks quite interesting.
[video=youtube;YfUAY41F5KE]http://www.youtube.com/watch?v=YfUAY41F5KE[/video]
The crystals in the paint are orange when above 26 degrees C, and go clear below.

 

[sarah]

Just like my Hotwheels cars did when I was a kid!! I spent hours in the bathroom running the hot and cold taps!

 

[TransAmDan]

I had a look for them hot wheels cars, but they don't do it that way any more. They seem to have some torch thingy giving the car light and that changes the colour. http://www.amazon.co.uk/Hot-Wheels-Ultimate-Speeders-Changing/dp/B00C2495QM less mess as no water required.