I ordered one of these that change color for a jam jar jet effect, which looks like a cherry blossom coming to life. Maybe I'll make the methanol burn green with boric acid to contrast the pink or lithium chloride for a brighter red. Wonder if the higher heat will bring out any more color or not?
Also this demo shows other glass color changes with heat which would be fun added effect for a jam jar jet.
Funny, I just saw a commercial for Transitions lenses that change color stepping outside. But a blurb at the bottom of the commercial in fine print said the photochromic effect is dependent on temperature, UV, and lens material. I always thought it was just UV that did it.
Maybe you could have a pair of those sunglasses near a jam jar jet enough so that they would transition when the jam jar was lit. At any rate being a plastic coating or laminate in glass, most photochromic materials won't stand up to direct heat for long.
On photosensitive glass ...
Military applications Edit
One of the reasons for the delay between the invention of photosensitive glass and its public announcement approximately ten years later was its potential use in military applications. It is possible to burn images and words that are hidden in photosensitive glass until heated at a high temperature. The military used this fact during World War II to send secret messages to allied troops in pieces of what looked like "ordinary glass". At the other end, the person who received the "ordinary glass" just had to heat it up to read the hidden message. Because of this application photosensitive glass was kept secret until the end of World War II.
The United Nations Building was faced with hundreds of square feet of photosensitive glass  until its 2007 refurbishment when it was replaced with conventional glass with a printed pattern 
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