Scrivener supports Themes. MacOS and Windows Themes are not compatible. Windows Themes are more powerful.
A macOs stheme is a combination of properties saved to file, a Windows Theme scrtheme is a combination of an xml manifest, a pal palette, a prefs Preferences file and a QSS Stylesheet in a Zipped package.
Currently, this forum has two pages where to find Themes: macOs Themes and Windows Themes. Light Themes are White and White Satin.
Resources for creating Themes you can find here at the forum, in the book Mastering Scrivener and the upcoming book Mastering Scrivener Themes. And there’s the subreddit /rScrivenerThemeBuilder.
I don’t know the Themes you mention. Can you link to pictures? How are they making “big waves”?