darkBlue top-level property Null safety

Implementation

NBColor darkBlue = const NBColor(
    0xff0077e6,
    <String, Color>{
      'darkBlue.50 ': Color(0xffdbf4ff),
      'darkBlue.100': Color(0xffaddbff),
      'darkBlue.200': Color(0xff7cc2ff),
      'darkBlue.300': Color(0xff4aa9ff),
      'darkBlue.400': Color(0xff1a91ff),
      'darkBlue.500': Color(0xff0077e6),
      'darkBlue.600': Color(0xff005db4),
      'darkBlue.700': Color(0xff004282),
      'darkBlue.800': Color(0xff002851),
      'darkBlue.900': Color(0xff000e21),
    },
    'darkBlue');