Migrate a Flutter App from Color.withOpacity to Color.withValues (Flutter 3.27+)
Replace the deprecated Color.withOpacity, opacity, value, red, green, blue and alpha with withValues, .a/.r/.g/.b and toARGB32. What dart fix rewrites for you, the four getters it leaves behind, why exact color assertions and Map<Color, T> lookups break after the swap, and how withOpacity silently drops Display P3. Measured on Flutter 3.44.8 with Dart 3.12.2.