iOS 18 Auto-Applied Gradient on Simple App Icons
iOS 18 introduced dark and tinted modes for app icons. Normal icons also got an update, the system automatically applies a gradient color treatment to icons it considers "simple".
Apple describes the behavior as crafted "intelligently to preserve design intent and maintain legibility", but the exact algorithm is undocumented. I did some basic tests to determe what is considered complex enough to skip this gradient.
What makes an icon simple
- Only 2 colors
- More than 2 colors, but 2 dominate and the rest appear minimally
What makes an icon complex
- Enough color variation across the icon
- Likely also gradients or complex shapes
Examples
Flat, single-color glyph. No decorative elements, outlines, or dark pixels, gradient applied automatically.
Has a bow/ribbon shape. The decorative curves prevent automatic treatment.
Built with visible outlines. Stroke heavy design breaks the tint pass. Click on icon to zoom in.
Contains black pixels. Dark areas conflict with the gradient's lightness model.
Sources
"The system's automatically generated treatment … is crafted intelligently to preserve design intent and maintain legibility."