Subject: molecule changes:chameleons vs photochromic produc

I am doing a science project.I am interested in how chameleons change 
colors and what this has in common with some consumer products that change 
colors when exposed to heat or cold or sometimes light. I have seen nail 
polish, tee shirts, toys, and baby spoons that change colors. I know that 
chameleons and these products involve pigment that is chemically changed 
by heat, light, or "mood." I dont really understand how this works. In the 
case of the chameleon, I have found a lot of information, but all I can 
find about consumer products is advertising and sales sites that dont tell 
how the products work. Can you help me or direct me to some sites? thanks.

Re: molecule changes:chameleons vs photochromic produc