Theming

Prism's theme is a set of @Immutable token tables exposed through CompositionLocals and accessed via the PrismTheme object. It follows the custom design system pattern recommended for Compose — not a fork of Material's own theme.

PrismTheme

@Composable
fun PrismTheme(
    colorScheme: PrismColorScheme = if (isSystemInDarkTheme()) PrismColorScheme.Dark else PrismColorScheme.Light,
    brand: PrismBrand = appleBrand,
    content: @Composable () -> Unit,
)

It does two things:

1. Provides Prism tokens — LocalPrismColors, LocalPrismTypography, LocalPrismSpacing, LocalPrismRadius, LocalPrismElevation, LocalPrismMotion, LocalPrismDimensions, LocalPrismMaterials.
2. Maps onto Material 3 — turns Prism colors into a ColorScheme so Material 3 controls (Switch, OutlinedTextField, NavigationBar, …) inherit the brand automatically.

Reading tokens

@Composable
fun Price(text: String) {
    Text(
        text = text,
        style = PrismTheme.typography.headline,
        color = PrismTheme.colors.accent,
        modifier = Modifier.padding(PrismTheme.spacing.s3),
    )
}

Accessor	Holds
PrismTheme.colors	26 semantic colors (accent, bg, labelPrimary, separator, tint*Bg, materialBg, focusRing, …)
PrismTheme.typography	largeTitle · title1 · title2 · headline · body · subhead · footnote
PrismTheme.spacing	s1…s7 (4-based, 8pt rhythm)
PrismTheme.radius	pill · card · modal · sheet · input · inner · image · sm
PrismTheme.elevation	level1…level4 · card
PrismTheme.motion	easings (easeStandard, …) + durations (durStandard, …)
PrismTheme.dimensions	control heights, touch target, focus-ring width
PrismTheme.materials	blur radii (blurThin · blurRegular · blurThick)

Light & dark

PrismTheme defaults to the system setting via isSystemInDarkTheme(). Force a scheme with the colorScheme parameter. Only colors differ between schemes — spacing, radius, type and motion are shared.

Brand presets

PrismTheme(brand = appleBrand)    { … }   // the default Apple-inspired look
PrismTheme(brand = neutralBrand)  { … }   // calm indigo, tighter geometry

A PrismBrand overrides accent + status colors and the radius geometry on top of the base scheme — the Compose equivalent of the web ThemeProvider's theme prop. Build your own by constructing a PrismBrand.

One token source

The token values are generated from a single source of truth — tokens/prism-tokens.json — by tokens/build-tokens.mjs, which emits both:

• the web CSS custom properties (src/styles/tokens.css), and
• the Kotlin token data classes (PrismGeneratedTokens.kt).

A parity check asserts the generated CSS is value-identical to the production web CSS (107 tokens), so web and Compose can never drift. See CSS theming (web) for the web side.