https://www.techradar.com/news/apple-watch-pride-face-and-strap-gallery

One of the announcements in the watchOS 5 section of WWDC 2018 was the fact that a new Watch face was being added to the mix: a rainbow-striped Pride face now available for free to any Watch user. 

Announced alongside was a matching Nylon Pride strap, being sold for $49 / £49 / AU$79, a white-and-rainbow number with donations being made to LGBTQ advocacy organizations Gender Spectrum, GLSEN, ILGA, PFLAG, The National Center for Transgender Equality and The Trevor Project.