Theming

This page describes how themes works in React Spectrum, including how applications adapt to operating system dark mode and touch scale.

Introduction#


React Spectrum is built to support theming. Colors, sizing, and spacing options can be customized through the use of CSS variables which are defined using the Provider component. Themes consist of variable definitions for light and dark color schemes, along with medium and large platform scales. Themes can also be nested to allow different parts of an application to adopt a different appearance.

Color schemes#


React Spectrum supports multiple color schemes within a theme, including light and dark mode. These correspond to color schemes found in popular operating systems. By default, React Spectrum automatically switches between color schemes according to the operating system setting using the prefers-color-scheme media query. This even updates automatically, so if a user changes their system's color scheme or it changes automatically (e.g. based on time of day), React Spectrum components will update accordingly.

We recommend that all React Spectrum applications support both light and dark mode. It can be very jarring to use a light themed application when the rest of your applications are in dark mode, and visa versa. This can be accomplished by using Spectrum color variables rather than hard coded color values. All React Spectrum components adapt to color scheme out of the box. See the styling page for details on how to use Spectrum color variables in your own custom components.

In case you need to override the operating system setting for some reason, e.g. an in-application setting, you can use the colorScheme prop on the Provider component. This can be set to "light" or "dark" to force the color scheme to a particular setting.

<Provider colorScheme="dark">
  <ActionButton margin="size-200">I'm a dark button</ActionButton>
</Provider>
<Provider colorScheme="dark">
  <ActionButton margin="size-200">
    I'm a dark button
  </ActionButton>
</Provider>
<Provider colorScheme="dark">
  <ActionButton margin="size-200">
    I'm a dark button
  </ActionButton>
</Provider>

Color schemes can also be nested. You could have a dark themed dialog inside a light themed application, for example. This might be useful for certain experiences like photo editing that are more optimal in dark mode, regardless of the operating system setting.

<Provider colorScheme="light">
  <ActionButton margin="size-200">I'm a light button</ActionButton>
  <Provider colorScheme="dark">
    <ActionButton margin="size-200">I'm a dark button</ActionButton>
  </Provider>
</Provider>
<Provider colorScheme="light">
  <ActionButton margin="size-200">
    I'm a light button
  </ActionButton>
  <Provider colorScheme="dark">
    <ActionButton margin="size-200">
      I'm a dark button
    </ActionButton>
  </Provider>
</Provider>
<Provider colorScheme="light">
  <ActionButton margin="size-200">
    I'm a light button
  </ActionButton>
  <Provider colorScheme="dark">
    <ActionButton margin="size-200">
      I'm a dark button
    </ActionButton>
  </Provider>
</Provider>

Platform scale#


In addition to color schemes, React Spectrum themes support multiple platform scales. There is a medium scale for devices with fine grained pointers (e.g. mice), and a large scale for devices with coarser grained input (e.g. touch). Large scale increases the size of most components so that they have larger hit targets. React Spectrum automatically switches between scales according to these device characteristics.

We strongly recommend keeping the default behavior and allowing your application to adapt to different devices. It can be especially hard to use applications with too small hit targets on touch devices, and annoying to use controls that are too large on desktop. That said, if you have some use case that requires it, you can explicitly set the scale prop on the Provider component to force a particular scale.

How themes are defined#


Themes are specified by passing a Theme object to the Provider component. This object includes several css modules which define the values for the variables in each color scheme and platform scale. Each CSS module defines a CSS class which includes the variables it defines, and Provider applies these classes according to media queries and prop settings.

React Spectrum includes two themes by default. The defaultTheme uses the Spectrum light and darkest color themes and is suitable for most applications. The darkTheme uses the Spectrum dark and darkest color themes, and is suitable for applications that are optimal with a darker interface regardless of operating system setting (e.g. photo/video editors). See the Spectrum color page for more information.

Import your desired theme and pass it to your application's Provider to apply it.

import {defaultTheme} from '@adobe/react-spectrum';

<Provider theme={defaultTheme}>
  <YourApp />
</Provider>
import {defaultTheme} from '@adobe/react-spectrum';

<Provider theme={defaultTheme}>
  <YourApp />
</Provider>
import {defaultTheme} from '@adobe/react-spectrum';

<Provider
  theme={defaultTheme}>
  <YourApp />
</Provider>

You can also build your own custom themes and apply them the same way. See the source code for the default theme for a list of variables that should be defined.