using System;

using System.Text.RegularExpressions;

using System.Globalization;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(new Regex("^(?:[0-9a-fA-F]{3,4}){1,2}$").IsMatch("8DB3E2"));

        SeriesColor str = new SeriesColor("#8DB3E2");

        Console.WriteLine(str.R);

        Console.WriteLine(str.G);

        Console.WriteLine(str.B);

        Console.WriteLine(str.A);

        Console.WriteLine(str.Hex);

    }

    internal struct SeriesColor

  {

​

    public SeriesColor(byte red, byte green, byte blue)

    {

      R = red;

      G = green;

      B = blue;

      A = 255;

    }

​

    public SeriesColor(byte red, byte green, byte blue, byte alpha)

    {

      R= red;

      G= green;

      B= blue;

      A= alpha;

    }

​

    public SeriesColor(string hex)

    {

      var str = ValidatedHexColor(hex);

      R = RfromHex(str);

      G = GfromHex(str);

      B = BfromHex(str);

      A = AfromHex(str);

    }

​

    public byte R;

    public byte G;

    public byte B;

    public byte A;

​

    public string Hex { 

      get

      {

        return "#" + R.ToString("X2") + G.ToString("X2") + B.ToString("X2") + (A==255?"":A.ToString("X2"));

      }

      set

      {

        var str = ValidatedHexColor(value);  

        R = RfromHex(str);

        G = GfromHex(str);

        B = BfromHex(str);

        A = AfromHex(str);

      }

    }

​

    private static string ValidatedHexColor(string value)

    {

      var str = value.TrimStart('#');

      if (!new Regex("^(?:[0-9a-fA-F]{3,4}){1,2}$").IsMatch(str)) throw new ArgumentException(value + " is not a valid hex color");

      if (str.Length == 3) str = new string(str[0], 2) + new string(str[1], 2) + new string(str[2], 2);

      if (str.Length == 4) str = new string(str[0], 2) + new string(str[1], 2) + new string(str[2], 2) + new string(str[3], 2);

      return str;

    } 

​

    private static byte RfromHex(string hex)

    {

      return byte.Parse(hex.Substring(0, 2), NumberStyles.HexNumber);

    }

​

    private static byte GfromHex(string hex)

    {

      return byte.Parse(hex.Substring(2, 2), NumberStyles.HexNumber);

    }

​

    private static byte BfromHex(string hex)

    {

      return byte.Parse(hex.Substring(4, 2), NumberStyles.HexNumber);

    }

​

    private static byte AfromHex(string hex)

    {

      return hex.Length != 8 ? (byte)255 : byte.Parse(hex.Substring(6, 2), NumberStyles.HexNumber);

    }

​

  }

}