thumbColor property

MaterialStateProperty<Color?>? thumbColor
final

The color of this Switch's thumb.

Resolved in the following states:

This example resolves the thumbColor based on the current MaterialState of the Switch, providing a different Color when it is MaterialState.disabled.
link 
Switch(
  value: true,
  onChanged: (bool value) { },
  thumbColor: MaterialStateProperty.resolveWith<Color>((Set<MaterialState> states) {
    if (states.contains(MaterialState.disabled)) {
      return Colors.orange.withOpacity(.48);
    }
    return Colors.orange;
  }),
)

If null, then the value of activeColor is used in the selected state and inactiveThumbColor in the default state. If that is also null, then the value of SwitchThemeData.thumbColor is used. If that is also null, then the following colors are used:

State Light theme Dark theme
Default Colors.grey.shade50 Colors.grey.shade400
Selected ColorScheme.secondary ColorScheme.secondary
Disabled Colors.grey.shade400 Colors.grey.shade800

Implementation

final MaterialStateProperty<Color?>? thumbColor;