Changing the trailing icon color in ExpansionTile

I need to change the color of the trailing keyboard_down_arrow in ExpansionTile. I have tried wrapping it in Theme widget and setting accent, primary and IconTheme also, but nothing seems to work.

Theme(
                  data: Theme.of(context).copyWith(
                    dividerColor: Colors.transparent,
                    accentColor: Colors.black,
                  ),
                  child: ExpansionTile(
                    //
                    title: Text("Some Text"
                    ),
                    childrenPadding: EdgeInsets.symmetric(horizontal: 15),
                    children: [
                      
                    ],
                  ),
                ),

I found the solution to the above problem.

set unselectedWidgetColor property to the color you want in Theme class in flutter.