navigationBarIndicatorOpacity property
Opacity used on the NavigationBar indicator.
If undefined and ThemeData.useMaterial3 is false then it defaults to 24%.
The default opacity is computed from kNavigationBarIndicatorAlpha
0x3D,
which is 61 giving 24% opacity.
This value is the same as Flutter SDK uses in Material 2. Material 3 may
often use no alpha and just different solid color hue instead.
The default value of this property may be adjusted later as Flutter
moves towards M3 designs. It might become 1.0.
Implementation
final double? navigationBarIndicatorOpacity;