axiom-hig

# Apple Human Interface Guidelines — Quick Reference

## When to Use This Skill

Use when:
- Making visual design decisions (colors, backgrounds, typography)
- Reviewing UI for HIG compliance
- Answering "Should I use a dark background?"
- Choosing between design options
- Defending design decisions to stakeholders
- Quick lookups for common design questions

#### Related Skills
- Use `axiom-hig-ref` for comprehensive details and code examples
- Use `axiom-liquid-glass` for iOS 26 material design implementation
- Use `axiom-liquid-glass-ref` for iOS 26 app-wide adoption guide
- Use `axiom-accessibility-diag` for accessibility troubleshooting

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## Quick Decision Trees

### Background Color Decision

```
Is your app media-focused (photos, videos, music)?
├─ Yes → Consider permanent dark appearance
│        WHY: "Lets UI recede, helps people focus on media" (Apple HIG)
│        EXAMPLES: Apple Music, Photos, Clock apps use dark
│        CODE: .preferredColorScheme(.dark) on root view
│
└─ No → Use system backgrounds (respect user preference)
         CODE: systemBackground (adapts to light/dark automatically)
         GROUPED: systemGroupedBackground for iOS Settings-style lists
```

**Apple's guidance:** "In rare cases, consider using only a dark appearance in the interface. For example, it can make sense for an app that enables immersive media viewing to use a permanently dark appearance."

### Color Selection Decision

```
Do you need a specific color value?
├─ No → Use semantic colors
│        label, secondaryLabel, tertiaryLabel, quaternaryLabel
│        systemBackground, secondarySystemBackground, tertiarySystemBackground
│        WHY: Automatically adapts to light/dark/high contrast
│
└─ Yes → Create Color Set in asset catalog
         1. Open Assets.xcassets
         2. Add Color Set
         3. Configure variants:
            ├─ Light mode color
            ├─ Dark mode color
            └─ High contrast (optional but recommended)
```

**Key principle:** "