toHex method
Prefixes a hash sign if leadingHashSign is set to true (default is true).
Implementation
String toHex({bool leadingHashSign = true}) => '${leadingHashSign ? '#' : ''}'
'${a._toRadixString(16).padLeft(2, '0')}'
'${r._toRadixString(16).padLeft(2, '0')}'
'${g._toRadixString(16).padLeft(2, '0')}'
'${g._toRadixString(16).padLeft(2, '0')}';