xdart-test/lib/MyColor.dart

class MyColor {
  String blue;
  String red;

  MyColor({this.blue, this.red});

  factory MyColor.fromJson(Map<String, dynamic> json) {
    return MyColor(
      blue: json['blue'],
      red: json['red'],
    );
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['blue'] = this.blue;
    data['red'] = this.red;
    return data;
  }
}