Thanks, @DTS Engineer. To be clear, the icon is not an image file (CMYK or otherwise). The icon was built using Icon Composer and imported into the project following these instructions. My main concern is that the icon in the App Store has changed without me taking any action. Since my initial post, the iOS App Store product page has now changed too. At 1:37 AM (first screenshot), it showed the expected icon. At 12:25 PM (second screenshot), the same product page now shows the modified icon. It's the exact same app version and build—not touched in two months. That makes this look less like a local previewing issue and more like an Apple-side issue in the pipeline that processes .icon files and caches the result.