How to change the DropdownButton's icon color? Flutter

Question

In Flutter, I am trying to change the color of the DropdownButton's icon (the down arrow icon) to white color.

I tried using the style property with no help. The text color became white but the icon is still the default grey.

DropdownButton(
         style: TextStyle(color: Colors.white, decorationColor: 
             Colors.white),
         items: this.items,
         value: null,
         hint: Text(SaveOptions[_saveOption], style: TextStyle(color: 
             Colors.white)),
         onChanged: (selectedOption) {
           setState(() {
             _saveOption = selectedOption;
           });
         })

How do I change the color of the arrow icon to white?

Answer 1

Since the DropdownButton gets the color from the nearest Theme, you have two options.

The first one is by changing the brightness of the application theme.

And the other is by wrapping your dropdown button with a new Theme with dark brightness.

Theme(
   data: Theme.of(context).copyWith(brightness: Brightness.dark),
   child: DropdownButton(
     style: TextStyle(color: Colors.white, decorationColor: Colors.white),
     items: this.items,
     value: null,
     hint: Text(SaveOptions[_saveOption], style: TextStyle(color: Colors.white)),
     onChanged: (selectedOption) {
       setState(() {
         _saveOption = selectedOption;
       });
     },
   ),
 )