private void ChangeToCMYK_Click(object sender, RoutedEventArgs e)
        {
            CmykColor color = ConvertRgbToCmyk(R.Value.GetValueOrDefault(),
                                               G.Value.GetValueOrDefault(),
                                               B.Value.GetValueOrDefault());

            C.Value = (double)color.C * 100;
            M.Value = (double)color.M * 100;
            Y.Value = (double)color.Y * 100;
            K.Value = (double)color.K * 100;
        }
        private void ColorPicker1_SelectedColorChanged(object sender, RoutedPropertyChangedEventArgs <Color?> e)
        {
            R.Value = ColorPicker1.SelectedColor.Value.R;
            G.Value = ColorPicker1.SelectedColor.Value.G;
            B.Value = ColorPicker1.SelectedColor.Value.B;

            CmykColor color = ConvertRgbToCmyk(ColorPicker1.SelectedColor.Value.R,
                                               ColorPicker1.SelectedColor.Value.G,
                                               ColorPicker1.SelectedColor.Value.B);

            C.Value = (double)color.C * 100;
            M.Value = (double)color.M * 100;
            Y.Value = (double)color.Y * 100;
            K.Value = (double)color.K * 100;
        }