Tencel denim shirt, a different kind of denim blue.

https://lorvell.com/en/blogs/%E9%A6%AC%E7%99%BB%E9%80%B1%E6%8E%A8%E8%96%A6/%E5%A4%A9%E7%B5%B2%E7%89%9B%E4%BB%94%E8%A5%AF%E8%A1%AB-%E4%B8%8D%E4%B8%80%E6%A8%A3%E7%9A%84%E4%B8%B9%E5%AF%A7%E8%97%8D