toHex method
Implementation
String toHex({bool leadingHashSign = true, bool includeAlpha = false}) {
final hex = includeAlpha
? toARGB32().toRadixString(16).padLeft(8, '0')
: toARGB32().toRadixString(16).padLeft(8, '0').substring(2);
return '${leadingHashSign ? '#' : ''}$hex'.toUpperCase();
}