ant-design/docs/react/demo/local-theme.tsx

import React from 'react';
import { Button, ConfigProvider, Space } from 'antd';

const App: React.FC = () => (
  <ConfigProvider
    theme={{
      token: {
        colorPrimary: '#1677ff',
      },
    }}
  >
    <Space>
      <Button type="primary">Theme 1</Button>
      <ConfigProvider
        theme={{
          token: {
            colorPrimary: '#00b96b',
          },
        }}
      >
        <Button type="primary">Theme 2</Button>
      </ConfigProvider>
    </Space>
  </ConfigProvider>
);

export default App;