theme-management

# Theme Management — Expert Decisions

Expert decision frameworks for theming choices in SwiftUI. Claude knows Color and colorScheme — this skill provides judgment calls for when custom theming adds value and architecture trade-offs.

---

## Decision Trees

### Do You Need Custom Theming?

```
What's your color requirement?
├─ Standard light/dark mode only
│  └─ System colors are sufficient
│     Color(.systemBackground), Color(.label)
│
├─ Brand colors that differ from system
│  └─ Asset catalog colors (Named Colors)
│     Define light/dark variants in xcassets
│
├─ User-selectable themes (beyond light/dark)
│  └─ Full ThemeManager with custom palettes
│     User can choose "Ocean", "Forest", etc.
│
└─ White-label app (different branding per client)
   └─ Remote theme configuration
      Fetch brand colors from server
```

**The trap**: Building a ThemeManager for an app that only needs light/dark mode. Asset catalog colors already handle this automatically.

### Color Token Architecture

```
How should you organize colors?
├─ Small app (< 20 screens)
│  └─ Direct Color("name") usage
│     Don't over-engineer
│
├─ Medium app, single brand
│  └─ Color extension with static properties
│     Color.appPrimary, Color.appBackground
│
├─ Large app, design system
│  └─ Semantic tokens + primitive tokens
│     Primitives: blue500, gray100
│     Semantic: textPrimary → gray900/gray100
│
└─ Multi-brand/white-label
   └─ Protocol-based themes
      protocol Theme { var primary: Color }
```

### Theme Switching Strategy

```
When should theme changes apply?
├─ Immediate (all screens at once)
│  └─ Environment-based (@Environment(\.colorScheme))
│     System handles propagation
│
├─ Per-screen animation
│  └─ withAnimation on theme property change
│     Smooth transition within visible content
│
├─ Custom transition (like morphing)
│  └─ Snapshot + crossfade technique
│     Complex, usually not worth it
│
└─ App restart required
   └─ For deep UIKit integration
      Sometimes