accentColor property Null safety
Obsolete property that was originally used as the foreground color for widgets (knobs, text, overscroll edge effect, etc).
Apps should migrate uses of this property to the theme's colorScheme ColorScheme.secondary color. In cases where a color is needed that that contrasts well with the secondary color ColorScheme.onSecondary can be used.
@Deprecated( 'Use colorScheme.secondary instead. ' 'For more information, consult the migration guide at ' 'https://flutter.dev/docs/release/breaking-changes/theme-data-accent-properties#migration-guide. ' 'This feature was deprecated after v2.3.0-0.1.pre.', ) Color get accentColor => _accentColor!;