@tarojs/cli/templates/default/src/app.config.js

cli tool for taro

export default defineAppConfig({
  pages: [
    'pages/index/index'
  ],
  window: {
    backgroundTextStyle: 'light',
    navigationBarBackgroundColor: '#fff',
    navigationBarTitleText: 'WeChat',
    navigationBarTextStyle: 'black'
  }
})