Primer Primitives

This repo contains values for color, spacing, and typography primitives for use with Primer, GitHub's design system.

Install

This repository is distributed on npm. After installing npm, you can install @primer/primitives with this command.

npm install --save @primer/primitives

Usage

Storybook | Docs

See Primitives documentation for more information on theming and using CSS variables.

Data is served from the dist/ folder:

dist/css contains CSS files with values available as CSS variables

All available imports:

/* size/typography */
@import '@primer/primitives/dist/css/base/size/size.css';
@import '@primer/primitives/dist/css/base/typography/typography.css';
@import '@primer/primitives/dist/css/functional/size/border.css';
@import '@primer/primitives/dist/css/functional/size/breakpoints.css';
@import '@primer/primitives/dist/css/functional/size/size.css';
@import '@primer/primitives/dist/css/functional/size/viewport.css';
@import '@primer/primitives/dist/css/functional/typography/typography.css';

/* color */
@import '@primer/primitives/dist/css/functional/themes/light.css';
@import '@primer/primitives/dist/css/functional/themes/light-tritanopia.css';
@import '@primer/primitives/dist/css/functional/themes/light-high-contrast.css';
@import '@primer/primitives/dist/css/functional/themes/light-colorblind.css';
@import '@primer/primitives/dist/css/functional/themes/dark.css';
@import '@primer/primitives/dist/css/functional/themes/dark-colorblind.css';
@import '@primer/primitives/dist/css/functional/themes/dark-dimmed.css';
@import '@primer/primitives/dist/css/functional/themes/dark-high-contrast.css';
@import '@primer/primitives/dist/css/functional/themes/dark-tritanopia.css';

Design token data

Design token data is stored in the src/tokens directory. These tokens are compiled with style dictionary in scripts/buildTokens.ts.

To make working with tokens easier, we added some additional functionality on top of what style dictionary comes with:

Extending and Overwriting

We have two main color modes: light and dark. Additionally we have specific accessibility modes based on those, such as light high contrast.

We added a way to create a mode by only including the changes from the main mode. We call this overrides. Overrides are cerated in src/tokens/functional/color/[light|dark]/overrides/ and have to be added to themes.config.ts to work. In the individual files, e.g. light.high-contrast.json5 you can now add tokens in the same structure as in any main file, e.g. primitives-light.json5 to replace them.

Transforming Colors with Alpha and Mix

Alpha

You can create color tokens that inherit a color but have a different alpha value by adding the alpha property. Note: The original alpha value will be replaced by your value. If you add alpha: 0.4 to a color, it doesn't matter if the color you reference has no alpha or alpha: 0.7, the new token will always have newly the defined value of alpha: 0.4.

{
  muted: {
    $value: '{base.color.blue.3}',
    alpha: 0.4, // the opacity value of the color === 40% opaque
    $type: 'color',
  },
}

Mix

In rare cases, you may need to create a color between two steps in the color scale, e.g. between gray.4 and gray.5. A common example are interactive states, like hover where a full step on the color scale would be to much. For those cases you can use the mix property.

The mix proeprty mixes the color it gets into the main color from the $value attribute. The amount added is controlled by the weight. A weight of 0.1 adds 10% of the color, and a weight of 0.75 adds 75%.

A mix proprty must always have a color and a weight child. color can be a hex value or a reference to a valid color. The weight property must receive a value between 0.0 and 1.

{
  control: {
    $value: '{base.color.gray.4}', // main color
    $type: 'color',
    mix: {
      color: '{base.color.gray.5}', // color to mix into the main color
      weight: 0.2, // amount of the mix color that is added === 20% of gray.5 is mix into gray.4
    },
  },
}

Extensions property

According to the w3c design token specs, the $extensions property is used for additional meta data.

For our Figma export we use the following meta data:

collection the collection that the token is added to within Figma
mode the mode that the token is added to within the collection in Figma
scopes the scopes that are assigned to the token in Figma, the actual Figma compatible scopes are retreive from an object in the figmaAttributes transformer

Code example

  bgColor: {
    $value: '{borderColor.accent.muted}',
    $type: 'color',
    $extensions: {
      'org.primer.figma': {
        collection: 'pattern/mode',
        mode: 'light',
        scopes: ['bgColor'],
      },
    },
  }

Token names and @-hack

Token names have to be in camelCase or kebab-case and may only include letters, numbers and -. This is enforced by the token validation (npm run lint:tokens). The only acception is the @-hack. This is used when you want to have a default value and sub-values, e.g. bgColor.accent and bgColor.accent.muted. In this case you can create the follwing structure. The @ will be removed from the name and act as the default value.

{
  bgColor: {
    accent: {
      '@': {
        // values for accent (default)
      },
      muted: {
        // values for accent-muted
      },
    },
  },
}