I am trying to draw a semi transparent rectangle and I keep getting an error when setting the textures data.

The size of the data passed in is too large or too small for this resource.

    dummyRectangle = new Rectangle(0, 0, 8, 8);
    Byte transparency_amount = 100; //0 transparent; 255 opaque
    dummyTexture = new Texture2D(ScreenManager.GraphicsDevice, 8, 8);
    Color[] c = new Color[1];
    c[0] = Color.FromNonPremultiplied(255, 255, 255, transparency_amount);
    dummyTexture.SetData<Color>(0, dummyRectangle, c, 0, 1);

the error is on the SetData line: "The size of the data passed in is too large or too small for this resource."

Any help would be appreciated.

Thank you.