It is said that the property of change in color of Thermochromic substances on heating can be used to visualize radio waves. Also they seem to have very interactive variation in colors as their temperature changes.
I agree with you. Thermochromic mateirals are very attractive and have many potential applications. I would like to share one recent work with you. Thanks for your attention.
Thermochromic behavior of chloro-nickel(II) in deep eutectic solvents and their application in thermochromic composite films. RSC Advances. 2011;1(7):1220-1227.http://dx.doi.org/10.1039/C1RA00345C