Changing form background color from a combobox.

Hey,
I'm trying to setup a combobox so a color selected will change the background.
I know I can name each color and direct it to the color by using -

Code:

private void button1_Click(object sender, EventArgs e)
        {
            string strColor = comboBox1.Text;
            Graphics g = this.CreateGraphics();
            switch (strColor)
            {
                {
                case "AliceBlue":
                    g.FillEllipse(new SolidBrush(Color.AliceBlue), 0, 0, 320, 220);
                    break;

- and copy and paste changing the "AliceBlue" names for each color.
but I'm sure there would be a way to borrow that name from the combobox.
for instant 'in any case put that case as the color'...

any help would be greatly appreciated.