OK, interesting: iOS 18 beta 3 seems to be doing an intelligent auto-dark tint on some third party app icons. It’s reliably triggered by being a clearly delineated shape on a white background. Other icons just get a slight ‘darkening’ effect applied.

BUT! check out that Facebook icon invert. Some kind of computational icon design happening here. Wild.

@sdw How does this get triggered, dark mode?
@jenzi You can set a theme to the icons in iOS 18. It’s either light, dark or colour tinted. This setting isn’t necessarily connected to light or dark mode, though you can do that.
It also applies to all icons equally and can’t be changed one by one.
@padraig Oh I see! I personally moved away from the platform with customizations for the one that just works so I would never uncover this on my own.