您可以像这样在 actionbar 中更改下拉菜单的背景颜色和文本颜色.

You can change the background color and text color of the dropdown menu in the actionbar like this.

在styles.xml中设置弹出菜单的样式.

Set the style for the popup menu in styles.xml.

 <style name="PopupMenuStyle" parent="Theme.AppCompat.Light">

         <item name="android:background">@color/YourColor</item>
         <item name="android:textColor">@Color/YourColor</item>

</style>

现在将这种样式设置为工具栏的 popupTheme .

Now set this style as the popupTheme for your toolbar.

<android.support.v7.widget.Toolbar  
      xmlns:app="http://schemas.android.com/apk/res-auto"          
      xmlns:android="http://schemas.android.com/apk/res/android"

          // rest of your code
      app:popupTheme="@style/PopupMenuStyle" />