```js
// Button.stories.js

// To apply a set of backgrounds to all stories of Button:
export default {
  title: 'Button',
  parameters: {
    backgrounds: {
      default: 'twitter',
      values: [
        { name: 'twitter', value: '#00aced' },
        { name: 'facebook', value: '#3b5998' },
      ],
    },
  },
};
```