Tribochromism refers to a change in colour of a material caused by mechanical friction, similar to piezochromism, the change in colour of a material caused by pressure.
It is a property of some materials and is often associated with thermochromism.
[1] Tribochromism and piezochromism are often grouped together under the term mechanochromism.
[2][3] Tribochromatic materials may be used in sensors when friction has to be detected.
These materials generally change colour under mechanical stress conditions; the colour gradually fades once the stress is removed.