Correct FAB color behavior when useMaterail3 is true

CHANGELOG.md

@@ -47,8 +47,8 @@ All notable changes to the **FlexColorScheme** package are documented here.
 
 **FIX**
 
-* **TODO** Style fix: Default color of Floating Action Button, when opting in on opinionated 
-  component themes, changed to match M3 default color `primaryContainer`.
+* **Style fix**: Default color of Floating Action Button, when opting in on `ThemeData.useMaterail3`
+  use M3 default color `primaryContainer`, otherwise use `secondary` as default.
 
 * **TODO** Style fix: Default color of highlight color on `NavigationBar` and `NavigationRail`,
   when opting in on opinionated component themes, changed to match M3 default color

example/lib/example5/widgets/panels/fab_toggle_chip_popup_settings/fab_toggle_chip_popup_settings.dart

@@ -56,7 +56,9 @@ class FabToggleChipPopupSettings extends StatelessWidget {
         const SizedBox(height: 8),
         ColorSchemePopupMenu(
           title: const Text('FloatingActionButton color'),
-          labelForDefault: 'default (secondary)',
+          labelForDefault: controller.useMaterial3
+              ? 'default (primaryContainer)'
+              : 'default (secondary)',
           index: controller.fabSchemeColor?.index ?? -1,
           onChanged: controller.useSubThemes && controller.useFlexColorScheme
               ? (int index) {

lib/src/flex_sub_themes.dart

@@ -1283,9 +1283,10 @@ class FlexSubThemes {
     ///
     /// All colors in the color scheme are not good choices, but some work well.
     ///
-    /// If not defined, or if passed in [colorScheme] is null, then
-    /// [theme.colorScheme.secondary] will be used via FAB widget's default
-    /// un-themed color behavior.
+    /// If not defined, or if passed in `colorScheme` is null, then if
+    /// `ThemeData.useMaterial3` is false `theme.colorScheme.secondary` will be
+    /// used, but if `ThemeData.useMaterial3` is true, then
+    /// `theme.colorScheme.primaryContainer` will be used.
     ///
     /// The foreground color automatically uses the selected background
     /// color's contrast color pair in the passed in [colorScheme] property.
@@ -1905,7 +1906,6 @@ class FlexSubThemes {
     /// the effective default styles for undefined inputs become:
     ///
     /// ```
-    /// ```
     ///                    FCS defaults   Flutter defaults
     /// useFlutterDefaults false          true
     /// - background       background     surface, + onSurface overlay elev 3.
@@ -1922,8 +1922,6 @@ class FlexSubThemes {
     /// [navigationBarMutedUnselectedIcon] and
     /// [navigationBarMutedUnselectedLabel] are true respectively, this
     /// also applies to undefined color inputs.
-    ///
-    /// ```
     final bool useFlutterDefaults = false,
   }) {
     // Determine if we can even use default icon styles, only when all are null,