Tango's [answer](https://scifi.stackexchange.com/questions/4159/which-episode-of-star-trek-tng-is-this-image-from/4161#4161) to "TNG crew in weird shopped rainbow hats" question mentioned that there was some sort of identifiable change to the color AND texture of Worf's sash.

The random images below seem to support this theory.

**Question: Was there an in-universe explanation for the change?**

***TNG 120 - Heart of Glory***

![enter image description here](https://i.stack.imgur.com/6YUvC.jpg)

***Season 2 Ep. 18 - Up The Long Ladder***

![enter image description here](https://i.stack.imgur.com/SDAFm.jpg)