Use Material with shadowColor inside Container like this:
Container(
decoration: BoxDecoration(
borderRadius: BorderRadius.only(
bottomLeft: Radius.circular(10),
bottomRight: Radius.circular(10)),
boxShadow: [
BoxShadow(
color: Color(0xffA22447).withOpacity(.05),
offset: Offset(0, 0),
blurRadius: 20,
spreadRadius: 3)
]),
child: Material(
borderRadius: BorderRadius.only(
bottomLeft: Radius.circular(10),
bottomRight: Radius.circular(10)),
elevation: 5,
shadowColor: Color(0xffA22447).withOpacity(.05),
color: Color(0xFFF7F7F7),
child: SizedBox(
height: MediaQuery.of(context).size.height / 3,
),
),
)