Getting Error while build in get-5.0.0-release-candidate-9.3.2

[hiteshsarsava]

../../../.pub-cache/hosted/pub.dev/get-5.0.0-release-candidate-9.3.2/lib/get_navigation/src/extension_navigation.dart:450:57: Error: The method 'withValues' isn't defined for the class 'MaterialColor'.
 - 'MaterialColor' is from 'package:flutter/src/material/colors.dart' ('../../../Documents/flutter/packages/flutter/lib/src/material/colors.dart').
Try correcting the name to the name of an existing method, or defining a method named 'withValues'.
        backgroundColor: backgroundColor ?? Colors.grey.withValues(alpha: 0.2),
                                                        ^^^^^^^^^^
../../../.pub-cache/hosted/pub.dev/get-5.0.0-release-candidate-9.3.2/lib/get_animations/animations.dart:376:45: Error: The getter 'a' isn't defined for the class 'Color'.
 - 'Color' is from 'dart:ui'.
Try correcting the name to the name of an existing getter, or defining a getter or field named 'a'.
              Color.lerp(begin, end, value!.a.toDouble())!,
                                            ^
Target kernel_snapshot_program failed: Exception


FAILURE: Build failed with an exception.