Switchable glass question (from transparent to a pure white)

[rasmusrasmusson]

Is there a material that changes from transparent to a pure white, ideally with reflective ability. Smart glass almost does this but falls short on it but being white enough (and not reflective).

 

[CWatters]

Not sure if this is good enough but check out Cloud Gel...

https://books.google.co.uk/books?id=rAAAAAAAMBAJ&pg=PA102&lpg=PA102&dq=heat+plastic+it+turns+white+clear+when+it+cools&source=bl&ots=7U6YiEY6zZ&sig=5eZUx0Ol3XSmehZ5W1el5mxGcFw&hl=en&sa=X&ved=0ahUKEwik48bLir3RAhUMLMAKHVefBaQQ6AEIKjAD#v=onepage&q=heat plastic it turns white clear when it cools&f=false

Oops I see that reference was from 1984.