shadowColor property
The color to paint the shadow below the material.
If null and ThemeData.useMaterial3 is true then ThemeData's ColorScheme.shadow will be used. If ThemeData.useMaterial3 is false then ThemeData.shadowColor will be used.
To remove the drop shadow when elevation is greater than 0, set shadowColor to Colors.transparent.
See also:
ThemeData.useMaterial3, which determines the default value for this property if it is null. ThemeData.applyElevationOverlayColor, which turns elevation overlay on or off for dark themes.
Implementation
final Color? shadowColor;