// Color 
Color _color = Colors.green;
_color = Color.fromRGBO(random.nextInt(256), random.nextInt(256), random.nextInt(256), 1,);

//border Radius
BorderRadiusGeometry _borderRadius = BorderRadius.circular(8);

decoration: BoxDecoration(
  color: _color,
  borderRadius: _borderRadius,
),

//Icon
Icon(Icons.play_arrow)