# NixOS design system

> NixOS design system measured from nixos.org: Route159 font, #28395F primary on #3B5487, 10 color hex codes, type scale, spacing and a free DESIGN.md.

Canonical page: https://sitepeel.dev/design-md/nixos.org/

NixOS’s website (nixos.org) uses the Route159 font and #28395F as its main color on a #3B5487 background. Measured by Sitepeel on November 4, 2026.

## What font does NixOS use?

NixOS uses Route159 (weight 700) and Roboto Flex Variable (weights 300 and 700) on nixos.org. Page titles are 61px at weight 700 and body text is 16px. Measured on November 4, 2026.

- Route159 (weights 700)
- Roboto Flex Variable (weights 300, 700)

## NixOS colors: palette and hex codes

NixOS’s main colors are #3B5487 (blue) for the background, #FFFFFF (white) for text and #28395F (dark blue) as the main accent, with #4D6FB7 (blue) and #A4D5F7 (light blue) as other accents. Measured on November 4, 2026.

- #3B5487: blue
- #FFFFFF: white
- #EEEEEE: mist
- #000000: near black
- #0B0B0B: near black
- #506FB2: blue
- #28395F: dark blue
- #4D6FB7: blue

## What is NixOS built with?

NixOS’s website (nixos.org) is built with Astro, Tailwind CSS and Netlify. Measured on November 4, 2026.

- JavaScript framework: Astro 7.4.2
- Hosting & CDN: Netlify
- UI & CSS: Tailwind CSS 4.x

## Questions and answers

### What font does NixOS use?

NixOS’s website uses Route159 (weight 700) and Roboto Flex Variable (weights 300 and 700). Page titles are 61px at weight 700 and body text is 16px. Measured on November 4, 2026.

### What are the NixOS colors and hex codes?

On nixos.org: #3B5487 (blue) for the background, #FFFFFF (white) for text and #28395F (dark blue) as the main accent, with #4D6FB7 (blue) and #A4D5F7 (light blue) as other accents. The color palette above lists all 10 colors with their hex codes and where each one is used.

### What is the NixOS design system?

The design system on this page is nixos.org’s, as measured on November 4, 2026: Route159 type, #28395F as the main color and 16px corners, written down as a DESIGN.md. It is not NixOS’s own documentation.

### What is NixOS built with?

NixOS’s website (nixos.org) is built with Astro, Tailwind CSS and Netlify. Measured on November 4, 2026.

### What is the NixOS DESIGN.md?

A plain-text file with NixOS’s measured colors, type, spacing, corners and components as tokens, plus short rules, in the DESIGN.md format Google published with Stitch. Your AI coding agent reads it and builds in this style. More about DESIGN.md.

### How do I use it with Claude Code or Cursor?

Download the file and put it in your project’s root folder, then ask your agent to follow DESIGN.md. Step-by-step guides: Claude Code, Cursor, Codex, GitHub Copilot.

### Is this NixOS’s official design system?

No. Sitepeel measured it from nixos.org’s public page on November 4, 2026. It is an independent analysis, not made or approved by NixOS.

### Can I use NixOS’s style in my own product?

Use it to learn, prototype and compare. For a real product, make the style your own, and never copy NixOS’s logo, name, pictures or text.

### How accurate are the values?

Each value was measured on the rendered page after it fully loaded, on desktop and mobile: colors where they appear, type with tracking, spacing, corners, shadows and hover states. Sites change, so check the date at the top.

## Files

- [DESIGN.md](https://sitepeel.dev/design-md/nixos.org/DESIGN.md): the plain file to put in your project.
- [All brand DESIGN.md files](https://sitepeel.dev/design-md/examples/index.md)

Independent analysis by Sitepeel (sitepeel.dev), not affiliated with NixOS.

## The DESIGN.md file

```markdown
---
version: alpha
name: NixOS
description: "Dark interface measured from nixos.org: Route159 type with Roboto Flex Variable, dark blue accents, flat surfaces and 16px corners."
colors:
  background: "#3B5487"
  surface: "#3B5487"
  on-surface: "#FFFFFF"
  on-background: "#FFFFFF"
  on-surface-variant: "#EEEEEE"
  on-surface-muted: "#000000"
  on-surface-subtle: "#0B0B0B"
  outline: "#506FB2"
  primary: "#28395F"
  on-primary: "#FFFFFF"
  secondary: "#4D6FB7"
  tertiary: "#A4D5F7"
typography:
  headline-display:
    fontFamily: Route159
    fontSize: 61px
    fontWeight: 700
    lineHeight: 1.25
  headline-lg:
    fontFamily: Route159
    fontSize: 39px
    fontWeight: 700
    lineHeight: 1.25
  headline-md:
    fontFamily: Route159
    fontSize: 22.5px
    fontWeight: 700
    lineHeight: 1.5
  body-md:
    fontFamily: Roboto Flex Variable
    fontSize: 16px
    fontWeight: 300
    lineHeight: 1.5
  body-lg:
    fontFamily: Route159
    fontSize: 19px
    fontWeight: 700
    lineHeight: 1.5
  body-sm:
    fontFamily: Roboto Flex Variable
    fontSize: 14px
    fontWeight: 300
    lineHeight: 1
  label-md:
    fontFamily: Roboto Flex Variable
    fontSize: 16px
    fontWeight: 700
    lineHeight: 1.5
rounded:
  sm: 16px
  md: 24px
spacing:
  xs: 4px
  sm: 8px
  md: 10px
  lg: 24px
  xl: 64px
  gutter: 16px
  section: 112px
components:
  button-primary:
    backgroundColor: "{colors.primary}"
    textColor: "{colors.on-primary}"
    typography: "{typography.body-sm}"
    rounded: "{rounded.sm}"
    padding: 10px 14px
    height: 62px
  button-outline:
    backgroundColor: "{colors.background}"
    textColor: "{colors.on-surface}"
    typography: "{typography.label-md}"
    rounded: "{rounded.sm}"
    padding: 8px 24px
    height: 40px
  button-secondary:
    backgroundColor: "{colors.secondary}"
    textColor: "{colors.on-surface}"
    typography: "{typography.label-md}"
    rounded: "{rounded.md}"
    padding: 10px 32px
    height: 44px
  button-ghost:
    typography: "{typography.label-md}"
    rounded: "{rounded.md}"
    padding: 10px 32px
  link:
    textColor: "{colors.on-surface-variant}"
---

# NixOS Design System

## Overview

NixOS describes itself as: “Nix is a tool that takes a unique approach to package management and system configuration. Learn how to make reproducible, declarative and reliable systems.” The interface is dark, built on **Blue (#3B5487)** with **White (#FFFFFF)** text, and **Dark Blue (#28395F)** as the main accent.

Type is set in **Route159** and **Roboto Flex Variable**. Headlines run large; body text is 16px. The surface language is flat. Corners are mostly 16px.

Measured from [nixos.org](https://nixos.org/) on November 4, 2026 at 1440×900 and 390×844 from 218 rendered elements. Values are computed styles from the live page, not the original source files.

## Colors

The palette has 10 roles.

- **Blue (#3B5487):** Page background, seen 3 times. Token `background`.
- **White (#FFFFFF):** Primary text and headings, seen 30 times. Token `on-surface`, CSS `--tw-ring-offset-color`.
- **Mist (#EEEEEE):** Secondary text, seen 21 times. Token `on-surface-variant`.
- **Near Black (#000000):** Muted text and metadata, seen 2 times. Token `on-surface-muted`.
- **Near Black (#0B0B0B):** Subtle text and placeholders, seen 5 times. Token `on-surface-subtle`.
- **Blue (#506FB2):** Borders and dividers, seen 15 times. Token `outline`.
- **Dark Blue (#28395F):** Brand color on large areas, seen 10 times. Token `primary`.
- **White (#FFFFFF):** Text and icons on primary. Token `on-primary`.
- **Blue (#4D6FB7):** Secondary buttons, seen 21 times. Token `secondary`.
- **Light Blue (#A4D5F7):** Accent in text, fills and borders, seen 10 times. Token `tertiary`.

## Typography

**Route159** and **Roboto Flex Variable** share the interface. Fallback stack: `Route159, -apple-system, BlinkMacSystemFont, Segoe UI`.

- **headline-display:** Route159 61px at weight 700, line height 1.25. Page title (h1).
- **headline-lg:** Route159 39px at weight 700, line height 1.25. Section headings (h2).
- **headline-md:** Route159 22.5px at weight 700, line height 1.5. Sub-section headings.
- **body-md:** Roboto Flex Variable 16px at weight 300, line height 1.5. Body text.
- **body-lg:** Route159 19px at weight 700, line height 1.5. Lead paragraphs.
- **body-sm:** Roboto Flex Variable 14px at weight 300, line height 1. Secondary and small text.
- **label-md:** Roboto Flex Variable 16px at weight 700, line height 1.5. Buttons, navigation and labels.

## Layout

Spacing is mostly on a 4px grid (73% of measured values), with some off-grid steps. Match the measured scale rather than rounding everything.

- **Scale:** xs 4px, sm 8px, md 10px, lg 24px, xl 64px.
- **Sections:** 112px vertical padding between major sections.
- **Gaps:** 16px is the most common gap in flex and grid layouts.

## Elevation & Depth

The design is flat: no shadows were measured. Hierarchy comes from color contrast and #506FB2 borders.

## Shapes

Most elements use 16px corners. Measured radii, most used first:

- **sm (16px):** 48 elements.
- **md (24px):** 4 elements.

## Components

Measured from the rendered page. Token values reference the tokens above.

- **button-primary (“Explore”):** #28395F fill, #FFFFFF text, 14px/300, 16px radius, padding 10px 14px.
- **button-outline (“Download Nix 2.35.4”):** #3B5487 fill, #FFFFFF text, 16px/700, 16px radius, padding 8px 24px.
- **button-secondary (“Search”):** #4D6FB7 fill, #FFFFFF text, 16px/700, 24px radius, padding 10px 32px.
- **button-ghost (“Search”):** transparent fill, 16px/700, 24px radius, padding 10px 32px.
- **link:** transparent fill, #EEEEEE text, padding 0px.

## Do's and Don'ts

- Do use #3B5487 for the page.
- Do keep text in 4 levels: #FFFFFF, #EEEEEE, #000000, #0B0B0B.
- Do use #28395F as the brand accent: header, logo and key highlights.
- Do reuse the measured spacing steps (8px, 10px, 24px).
- Do use 16px corners on most elements; larger surfaces also use 24px.
- Don't use #000000 for body text; it reaches 2.80:1 on #3B5487. Keep it for large text or metadata.
- Don't use #0B0B0B for body text; it reaches 2.63:1 on #3B5487. Keep it for large text or metadata.
- Don't add drop shadows for depth; use borders and contrast.
- Don't introduce new font families beyond Route159 and Roboto Flex Variable.
- Don't use #28395F for large backgrounds or body text.
- Don't make interface transitions slower than 0.3s.

## Motion

Interface transitions are quick: 0.3s, 0.15s.

- **Easing:** `cubic-bezier(0.4, 0, 0.2, 1)`.
- **Reduced motion:** the page responds to `prefers-reduced-motion`.

Generated by [Sitepeel](https://sitepeel.dev/design-md/nixos.org/), the free DESIGN.md generator (engine 2026.10.29+b828a475ee10).

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