Themes - Tamagui — ContextQMD

Themes map neatly to CSS variables: they are objects whose values you want to contextually change at any point in your React tree. They are used either as the first lookup for $ prefixed style values, or with the useTheme hook directly. Tamagui allows nesting themes - both the definition and at runtime. At runtime Tamagui resolves theme values upwards, ultimately all the way back to tokens.

For the recommended theme setup, see the Config v5 docs.

Once you've learned the basics here, be sure to check out the ThemeBuilder guide for generating more interesting theme suites.

If you want to style bento or tamagui components: see Styling tamagui UI components.

<Notice theme="green"> If you want a copy-paste theme generation setup, [try this gist](https://gist.github.com/natew/3be503cc5990a1142d17ffadf86a134f) for a well-structured example. </Notice>

You define a theme like this:

tsx

const dark = {
  background: '#000',
  color: '#fff',
  // define any key to any string or number value
}

If you use tokens, you can share values from tokens down to themes. Tokens act as fallback values for themes, like global CSS variables vs scoped ones:

tsx

const tokens = createTokens({
  color: {
    black: '#000',
    white: '#fff',
  },
})

// theme:
const dark = {
  background: tokens.color.black,
  color: tokens.color.white,
}

Sub-themes

One of the unique powers of Tamagui is theme nesting. Define a theme with a name in the form of parentName_subName and Tamagui will let you nest themes, with both parentName and subName being valid theme names.

You can do this as many times as you'd like. Here's an example of having three levels:

dark_green_subtle
light_green_subtle

tsx

<Theme name="dark">
  <Theme name="green">
    <Button theme="subtle">Hello world</Button>
  </Theme>
</Theme>

You can also access a specific sub-theme more specifically:

tsx

<Theme name="dark">
  <Button theme="green_subtle">Hello world</Button>
</Theme>

In general you want your themes to all be the same shape - the same named keys and typed values - but sub-themes can be sub-sets of parent themes. The useTheme hook and style system will resolve missing keys upwards to parent themes, and ultimately to tokens.

Component themes

Every Tamagui styled() component looks for its own specific theme if you pass it the name property. For example:

tsx

import { View, styled } from 'tamagui' // or '@tamagui/core'

const Circle = styled(View, {
  name: 'Circle',
  backgroundColor: '$background',
})

The name attribute will be removed from the defaultProps and used internally by Tamagui to check for a sub-theme that ends with _Circle.

Now you can create the default theme for all Circle components at any level of nesting:

tsx

const dark_Circle = {
  background: 'darkred',
  color: 'white',
}

const light_Circle = {
  background: 'lightred',
  color: 'black',
}

<Notice theme="blue">Component themes must have the first letter capitalized.</Notice>

dark_Circle
dark_green_Circle
dark_green_subtle_Circle

This is an incredibly powerful and unique feature that allows authors of UI components control over design, while still letting users customize them completely.

Styling Tamagui UI components

Tamagui comes in two parts: a core library and a full UI kit. The core library (@tamagui/core) is flexible and doesn't have many rules. But the full UI kit (tamagui) has some standard ways of doing things. This helps make everything work well together.

In the tamagui UI kit, all components use these main theme keys:

background: for background colors
color: for text colors
borderColor: for border colors
shadowColor: for shadow colors
placeholderColor: for placeholder text colors (doesn't change when you interact with it)

It also uses special versions of these for when you hover, press, or focus on something. For example, backgroundHover or colorPress.

These keys help standardize how you style components, and make for easy re-theming. They are also optional, if you find the theme system too complex for your use case, you can always just use plain old style props

...plus all the pseudo variants for each, eg, backgroundHover, backgroundPress, and backgroundFocus.

This means that you can easily re-theme tamagui's UI kit and your own components together in both light and dark mode.

A minimal theme might look like this:

tsx

const dark = {
  // Standard keys for all components
  background: '#000',
  backgroundHover: '#111',
  backgroundPress: '#222',
  backgroundFocus: '#333',
  backgroundStrong: '#444',
  backgroundTransparent: 'rgba(0, 0, 0, 0.5)',
  color: '#fff',
  colorHover: '#eee',
  colorPress: '#ddd',
  colorFocus: '#ccc',
  colorTransparent: 'rgba(255, 255, 255, 0.5)',
  borderColor: '#555',
  borderColorHover: '#666',
  borderColorFocus: '#777',
  borderColorPress: '#888',
  placeholderColor: '#999',
  outlineColor: '#aaa',
  // Custom tokens like "brand"
  brandBackground: '#000', // You can add your own tokens like "brand"
  brandColor: '#fff', // and use them in your components
}

const light = {
  // Standard keys for all components
  background: '#fff',
  backgroundHover: '#f5f5f5',
  backgroundPress: '#e0e0e0',
  backgroundFocus: '#d5d5d5',
  backgroundStrong: '#ccc',
  backgroundTransparent: 'rgba(255, 255, 255, 0.5)',
  color: '#000',
  colorHover: '#111',
  colorPress: '#222',
  colorFocus: '#333',
  colorTransparent: 'rgba(0, 0, 0, 0.5)',
  borderColor: '#444',
  borderColorHover: '#555',
  borderColorFocus: '#666',
  borderColorPress: '#777',
  placeholderColor: '#888',
  outlineColor: '#999',
  // Custom tokens like "brand"
  brandBackground: '#000', // You can add your own tokens like "brand"
  brandColor: '#fff', // and use them in your components
}

You can of course do all of this yourself in your own design system with styled:

If you are building a component with more than one sub-components, you can follow this pattern:

tsx

import { GetProps, View, Text, styled } from 'tamagui' // or '@tamagui/core'

const ButtonFrame = styled(View, {
  name: 'Button',
  backgroundColor: '$background',
})

const ButtonText = styled(Text, {
  name: 'ButtonText',
  color: '$color',
})

type ButtonProps = GetProps<typeof ButtonFrame>

// styleable() wraps a functional component so it can be further styled with styled()
// see /docs/core/styled#styleable for full documentation
export const Button = ButtonFrame.styleable<ButtonProps>(
  ({ children, ...props }, ref) => {
    return (
      <ButtonFrame ref={ref} {...props}>
        <ButtonText>{children}</ButtonText>
      </ButtonFrame>
    )
  }
)

And now you can add two themes: dark_Button and dark_ButtonText, and override their default styles.

Full Example

Let's start with an example of inline styling with a subset of the configuration:

tsx

import { TamaguiProvider, createTokens, createTamagui, View, Theme } from 'tamagui'

const tokens = createTokens({
  color: {
    darkRed: '#550000',
    lightRed: '#ff0000',
  },
  // ... see configuration docs for required tokens
})

const config = createTamagui({
  tokens,
  themes: {
    dark: {
      red: tokens.color.darkRed,
    },
    light: {
      red: tokens.color.lightRed,
    },
  },
})

export const App = () => (
  <TamaguiProvider config={config} defaultTheme="light">
    <View backgroundColor="$red" />
    <Theme name="dark">
      <View backgroundColor="$red" />
    </Theme>
  </TamaguiProvider>
)

In this example we've set up darkRed and lightRed variables and a dark and light theme that use those variables. Tamagui will handle defining:

css

:root {
  --colors-dark-red: #550000;
  --colors-light-red: #ff0000;
}

.tui_dark {
  --red: var(--colors-dark-red);
}

.tui_light {
  --red: var(--colors-light-red);
}

Which will automatically apply at runtime, or can be gathered for use in SSR using Tamagui.getCSS().

Finally, the compiler on web will extract your views roughly as so:

tsx

export const App = () => (
  <Provider defaultTheme="light">
    <div className="baCo-2nesi3" />
    <Theme name="dark">
      <div className="baCo-2nesi3" />
    </Theme>
  </Provider>
)

// CSS output:
//  .color-2nesi3 { background-color: var(--red); }

Ensuring valid types

Here's what we've landed on which helps ensure everything is typed properly. Keep themes in a separate themes.ts file, and structure it like this:

tsx

import { tokens } from './tokens'

const light = {
  background: '#fff',
  backgroundHover: tokens.color.gray3,
  backgroundPress: tokens.color.gray4,
  backgroundFocus: tokens.color.gray5,
  borderColor: tokens.color.gray4,
  borderColorHover: tokens.color.gray6,
  color: tokens.color.gray12,
  colorHover: tokens.color.gray11,
  colorPress: tokens.color.gray10,
  colorFocus: tokens.color.gray6,
  shadowColor: tokens.color.grayA5,
  shadowColorHover: tokens.color.grayA6,
}

// note: we set up a single consistent base type to validate the rest:
type BaseTheme = typeof light

// the rest of the themes use BaseTheme
const dark: BaseTheme = {
  background: '#000',
  backgroundHover: tokens.color.gray2Dark,
  backgroundPress: tokens.color.gray3Dark,
  backgroundFocus: tokens.color.gray4Dark,
  borderColor: tokens.color.gray3Dark,
  borderColorHover: tokens.color.gray4Dark,
  color: '#ddd',
  colorHover: tokens.color.gray11Dark,
  colorPress: tokens.color.gray10Dark,
  colorFocus: tokens.color.gray6Dark,
  shadowColor: tokens.color.grayA6,
  shadowColorHover: tokens.color.grayA7,
}

const dark_translucent: BaseTheme = {
  ...dark,
  background: 'rgba(0,0,0,0.7)',
  backgroundHover: 'rgba(0,0,0,0.5)',
  backgroundPress: 'rgba(0,0,0,0.25)',
  backgroundFocus: 'rgba(0,0,0,0.1)',
}

const light_translucent: BaseTheme = {
  ...light,
  background: 'rgba(255,255,255,0.85)',
  backgroundHover: 'rgba(250,250,250,0.85)',
  backgroundPress: 'rgba(240,240,240,0.85)',
  backgroundFocus: 'rgba(240,240,240,0.7)',
}

export const allThemes = {
  dark,
  light,
  dark_translucent,
  light_translucent,
} satisfies { [key: string]: BaseTheme }
// note: `satisfies` was introduced with TypeScript 4.9

Dynamic Themes

Sometimes you want to defer loading themes, or change existing theme values at runtime. Tamagui exports three helpers for this in the package @tamagui/theme which exports addTheme, updateTheme, and replaceTheme.

addTheme

tsx

updateTheme

tsx

replaceTheme

tsx

Notes

Dynamic themes only work on the client side and will be ignored on the server side.
The difference between updateTheme and replaceTheme is that replaceTheme will replace the entire theme, while updateTheme will only update the values that are passed in.

Advanced Optimization

You can configure Tamagui to not send any themes JS to the client side, so long as your are serving the resulting css file from the getCSS call on initial load of your app (SSR).

To enable this you need to have your bundler tree shake away the themes object you'd typically pass to createTamagui for the client bundle. Note this is a somewhat advanced optimization and not necessary to do right away.

tsx

import { themes as themesIn } from './your-themes-file'

// We leave this value empty for production client side bundles to save on bundle size.
// The `@tamagui/next-plugin` sets TAMAGUI_IS_SERVER automatically.
// If you pass an empty themes object Tamagui will try to hydrate by scanning CSS in browser environments.
// It typically takes low single-digit ms to scan and can save significantly on JS size.

const themes =
  process.env.TAMAGUI_IS_SERVER || process.env.NODE_ENV !== 'production'
    ? themesIn
    : ({} as typeof themesIn)

export const config = createTamagui({
  themes,
  // ...
})