Example

using System;
using System.Windows.Data;
using System.Windows.Media;

namespace ClientUI.Samples.Converters
{
    public class ColorConverter : IValueConverter
    {
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            SolidColorBrush colorBrush = (SolidColorBrush)value;

            string A = BitConverter.ToString(new byte[] { colorBrush.Color.A });
            string R = BitConverter.ToString(new byte[] { colorBrush.Color.R });
            string G = BitConverter.ToString(new byte[] { colorBrush.Color.G });
            string B = BitConverter.ToString(new byte[] { colorBrush.Color.B });

            return "#" + A + R + G + B;
        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            string colorString = value as string;

            if (colorString.Length != 9)
            {
                throw new Exception("Invalid format");
            }
            else
            {
                byte A = System.Convert.ToByte(colorString.Substring(1, 2), 16);
                byte R = System.Convert.ToByte(colorString.Substring(3, 2), 16);
                byte G = System.Convert.ToByte(colorString.Substring(5, 2), 16);
                byte B = System.Convert.ToByte(colorString.Substring(7, 2), 16);

                SolidColorBrush colorBrush = new SolidColorBrush(Color.FromArgb(A, R, G, B));
                return colorBrush;
            }            
        }
    }
}