Color changing paint display

We’ve seen several creative projects from [Sprite_tm] and this one sets a new bar. He got his hands on some paint that changes color with temperature. By covering a circuit board with the paint then heating the circuits he’s created a heat actuated 7-segment display (his post is in Dutch). Three seconds at about 1 amp is enough to turn the black paint white. When the segment has been disconnected for about one minute the paint fades back to black. Now that we’ve seen his concept, leave a comment and tell us how you’d use it.