Background piker color

<usercontrol x:class="WpfCoWorker.CoWorkerSeparatorControl"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
        xmlns:osc="clr-namespace:WpfCoWorker"
        Name="coworkercontrol"
        mc:Ignorable="d" 
        d:DesignHeight="300" d:DesignWidth="300">
    <border name="mainborder" removed="{Binding ElementName=colorpicker, Path=SelectedBrush}">
        <grid>
            <grid.columndefinitions>
                <columndefinition width="*" />
                <columndefinition width="22" />
            </grid.columndefinitions>
            <textbox name="texbox">
                    Margin="0"
                    Padding="0"
                    Grid.Column="0"
                    Height="Auto"
                    Background="{Binding ElementName=colorpicker, Path=SelectedBrush}"
                    Text="{Binding Text, RelativeSource={RelativeSource AncestorType=UserControl}}"/>
            <osc:comboboxcolorpicker x:name="colorpicker" xmlns:osc="#unknown">
                    SelectedColor="White"
                    ColorChanged="colorpicker_ColorChanged"
                    HorizontalAlignment="Left"
                    Grid.Column="1"/>
        </grid>
    </border>
</usercontrol>

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;

namespace WpfCoWorker
{
    public partial class CoWorkerSeparatorControl : UserControl
    {
        public String IText
        {
            get { return this.texbox.Text; }
        }
        public Color IColor
        {
            get { return this.colorpicker.SelectedColor; }
        }
        public String Text
        {
            get { return (String)GetValue(TextProperty); }
            set { SetValue(TextProperty, value); }
        }

        public static readonly DependencyProperty TextProperty =
            DependencyProperty.Register("Text", typeof(String),
              typeof(CoWorkerSeparatorControl), new PropertyMetadata(""));

        public Color BckColor
        {
            get { return (Color)GetValue(BckColorProperty); }
            set { SetValue(BckColorProperty, value); }
        }

        public static readonly DependencyProperty BckColorProperty =
            DependencyProperty.Register("BckColor", typeof(Color),
              typeof(CoWorkerSeparatorControl), new PropertyMetadata(Colors.Transparent));

        public CoWorkerSeparatorControl()
        {
            InitializeComponent();
        }
    }
}