nbColor top-level property Null safety

Implementation

NativeBaseColor nbColor = NativeBaseColor(
  amber,
  blue,
  blueGray,
  coolGray,
  cyan,
  dark,
  darkBlue,
  emerald,
  fuchsia,
  gray,
  green,
  indigo,
  lightBlue,
  lime,
  orange,
  pink,
  purple,
  red,
  rose,
  teal,
  text,
  trueGray,
  warmGray,
  yellow,
  white,
  black,
);