Temperature Sensitive Dyes

There are ways to make surfaces sensitive to temperature such that their color will change. The most common example is probably a child's toy that changes color when exposed to hot or cold water.

I would be interested to see if this basic concept could be used to make temperature sensitive dyes.

It could be neat to have a shirt that is white if it is hot out, but then changes color to black when it is cool. The practical benefit is that white reflects light and keeps you cool, where as black absorbs light and gets warmer.

A shirt could also be designed to change color based on what temperature it was washed in

Ultimately the practicality is limited. However, the same applies to a lot of fashion, and as a gimmick I think it would be a neat one.