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title: Tailwind CSS v4 default theme reference applies_to: [tailwindcss, oklch, design-tokens, web] version: 1.0.0 last_updated: 2026-05 stability: stable

Tailwind CSS v4 default theme

Tailwind v4 ships an OKLCH-based default theme that's the most commonly used token set in modern web product UIs. Worth knowing as a reference, even if you customize.

Theme syntax

Tailwind v4 uses CSS-native @theme declarations:

@import "tailwindcss";

@theme {
  --color-primary-500: oklch(0.606 0.250 292.717);
  --spacing: 0.25rem;
  --font-sans: 'Inter', sans-serif;
  /* ... */
}

Variables become utility classes automatically (bg-primary-500, p-4, font-sans).

Color scale (the hero feature)

Tailwind v4's default colors are OKLCH-derived. Each scale is perceptually uniform — step from 100 to 200 is visually the same magnitude as 800 to 900. This is the headline change from v3.

Color families

22 default color families × 11 steps each = 242 default colors. Listed below in OKLCH rotation order:

red, orange, amber, yellow, lime, green, emerald, teal, cyan,
sky, blue, indigo, violet, purple, fuchsia, pink, rose,
slate, gray, zinc, neutral, stone

The first 17 are chromatic; the last 5 are neutral grays with subtle hue tints.

Steps (per family)

50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 950

Lightness mapping (consistent across families)

Step Approximate OKLCH L
50 0.96–0.98
100 0.93–0.95
200 0.87–0.90
300 0.78–0.82
400 0.65–0.72
500 0.55–0.62
600 0.49–0.55
700 0.42–0.49
800 0.36–0.43
900 0.30–0.38
950 0.18–0.28

Step 600 hits ~4.5:1 on white for most chromatic colors — this is the canonical "primary brand" anchor. Step 500 hits ~3:1 (UI-sized only).

Sample family — violet

@theme {
  --color-violet-50:  oklch(0.969 0.016 293.756);  /* #F5F3FF */
  --color-violet-100: oklch(0.943 0.029 294.588);  /* #EDE9FE */
  --color-violet-200: oklch(0.894 0.057 293.283);  /* #DDD6FE */
  --color-violet-300: oklch(0.811 0.111 293.571);  /* #C4B5FD */
  --color-violet-400: oklch(0.702 0.183 293.541);  /* #A78BFA */
  --color-violet-500: oklch(0.606 0.250 292.717);  /* #8B5CF6 */
  --color-violet-600: oklch(0.541 0.281 293.009);  /* #7C3AED */
  --color-violet-700: oklch(0.491 0.270 292.581);  /* #6D28D9 */
  --color-violet-800: oklch(0.432 0.232 292.759);  /* #5B21B6 */
  --color-violet-900: oklch(0.381 0.176 293.745);  /* #4C1D95 */
  --color-violet-950: oklch(0.283 0.141 291.089);  /* #2E1065 */
}

Spacing

Tailwind v4 default uses a single --spacing base, with utilities scaling it:

@theme {
  --spacing: 0.25rem;  /* 4px (assuming 16px root) */
}
Class Value
p-1 4px
p-2 8px
p-3 12px
p-4 16px
p-5 20px
p-6 24px
p-8 32px
p-10 40px
p-12 48px
p-16 64px
p-20 80px
p-24 96px

Aligns with our 4-base scale per layout/spacing-and-grid.md.

Typography

@theme {
  --font-sans: ui-sans-serif, system-ui, sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', 'Noto Color Emoji';
  --font-serif: ui-serif, Georgia, Cambria, 'Times New Roman', Times, serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, 'Liberation Mono', 'Courier New', monospace;
}

System-font stacks are the default — performant, no FOUT.

Type scale

Class Size Line height
text-xs 12px 16px (1.33)
text-sm 14px 20px (1.43)
text-base 16px 24px (1.5)
text-lg 18px 28px (1.56)
text-xl 20px 28px (1.4)
text-2xl 24px 32px (1.33)
text-3xl 30px 36px (1.2)
text-4xl 36px 40px (1.11)
text-5xl 48px 1
text-6xl 60px 1
text-7xl 72px 1
text-8xl 96px 1
text-9xl 128px 1

Note: large sizes (5xl+) drop to line-height: 1 (display use). Body sizes have generous leading.

Weights

font-thin 100 / font-extralight 200 / font-light 300 / font-normal 400 / font-medium 500 / font-semibold 600 / font-bold 700 / font-extrabold 800 / font-black 900.

Breakpoints

@theme {
  --breakpoint-sm: 40rem;    /* 640px */
  --breakpoint-md: 48rem;    /* 768px */
  --breakpoint-lg: 64rem;    /* 1024px */
  --breakpoint-xl: 80rem;    /* 1280px */
  --breakpoint-2xl: 96rem;   /* 1536px */
}

Mobile-first: utilities apply at all sizes by default; md:bg-blue-500 applies at ≥ 768px.

Border radius

Class Value
rounded-none 0
rounded-sm 0.125rem (2px)
rounded 0.25rem (4px)
rounded-md 0.375rem (6px)
rounded-lg 0.5rem (8px)
rounded-xl 0.75rem (12px)
rounded-2xl 1rem (16px)
rounded-3xl 1.5rem (24px)
rounded-full 9999px

Shadows

shadow-2xs  / shadow-xs  / shadow-sm  / shadow  /
shadow-md  / shadow-lg  / shadow-xl  / shadow-2xl  /
shadow-inner  / shadow-none

Default values use rgb(0 0 0 / x) with varying offset and blur.

Transitions

Class Properties
transition most common (color, bg, border, opacity, shadow, transform, filter, backdrop-filter)
transition-all everything (avoid in production)
transition-colors color-only
transition-opacity opacity-only
transition-shadow shadow-only
transition-transform transform-only

Default duration 150ms, ease cubic-bezier(0.4, 0, 0.2, 1).

Class Duration
duration-75 75ms
duration-100 100ms
duration-150 150ms
duration-200 200ms
duration-300 300ms
duration-500 500ms
duration-700 700ms
duration-1000 1000ms

Consistent with motion/principles.md duration tiers.

Z-index scale

z-0, z-10, z-20, z-30, z-40, z-50, z-auto.

For component systems with modals/popovers/tooltips: extend with semantic z-tokens (--z-modal, --z-popover, etc.) above this default.

Dark mode

Tailwind v4 supports two strategies:

Media query (default)

.dark\:bg-slate-900 { ... }

Applied via @media (prefers-color-scheme: dark).

Class-based (most product apps)

@variant dark (&:where(.dark, .dark *));

Then <html class="dark"> toggles dark mode globally.

Token override

@theme {
  --color-bg: oklch(1 0 0);  /* white */
}

@layer base {
  .dark {
    --color-bg: oklch(0.18 0 0);  /* near-black */
  }
}

How to customize

To make Tailwind v4 yours:

  1. Override @theme with your brand tokens.
  2. Add semantic aliases: 
    @theme {
  --color-primary-default: var(--color-violet-600);
  --color-primary-hover: var(--color-violet-700);
}
  3. Drop unused color families if bundle size matters (Tailwind tree-shakes; minimal concern).

When NOT to use Tailwind v4 defaults

  • Brand has very specific palette: replace the chromatic families with your brand ramps.
  • Korean fintech needing red=up convention: replace --color-money-positive / --color-money-negative semantically; keep primary scale.
  • Material Design alignment: use Material 3 tokens instead — see material-3.md.
  • Apps where oklch() browser support matters (older browsers): provide hex fallbacks via PostCSS plugin or extract hex equivalents.

Worked example using Tailwind v4

See examples/palette-saas-violet.md for a complete palette generated from Tailwind v4 violet ramps.

Cross-reference