3D Printer Filaments that change color based on temperature or UV light
An example of a color changing filament is the thermochrome filament from Filaments.ca. A PLA based filament tht has an opaque anthracite grey color when the temperature of the material is below 29° C. However, when the material reaches a temperature of 29° C, or above, it will change into a transparent color.
Color changing filaments print just like normal PLA. The only difference is that an additive has been added, which enables this colour-changing feature, but should print as smoothly as normal PLA.