In case you're curious, I've checked the implementation for icon segmentation in iOS 18 to see how they're generating the dark icons. There's no ML/AI involved, it's all just clever math. IconServices extracts the foreground and determines whether it should be tinted with the background color or left as-is, and there are configurable thresholds for when the results are not acceptable, which is when it falls back to just darkening the icon. Looks like it uses ARM Neon instructions for speed