I created these Haiku OS themes and a wallpaper over the weekend. View the info file to see how to install. They require ThemeManager, which can be installed from HaikuDepot. I did not create the wallpaper in the dark them. Attribution in info file also.
The irritations: Things seem inconsistent in Haiku, it’s not a stable release and in heavy development so things could change. First, not all apps follow the theme 100%. Second, the text on desktop icons has odd behavior, at least on light backgrounds, but I could find nothing to disable the label or change the high light. Maybe there is a way to do it so if you know, drop me a comment.