you need change theme by adding

in my case i will use those colors

final ThemeData lightTheme = ThemeData(
  useMaterial3: false,

  brightness: Brightness.light,
  colorScheme: ColorScheme.fromSeed(
    seedColor: AppColors.baseColorOrange,
    primary: AppColors.baseColorOrange,
    secondary: const Color(0xFF03DAC6),
    background: const Color(0xFFF5F5F5),
    surface: const Color(0xFFFFFFFF),
  ),