QML: Animating the background of a rectangle also animates the border

import Qt 4.7

Rectangle {
    id: root
    width:300; height:200
    border.width: 50

    states: [
        State {
            when: focus
            PropertyChanges {
                target: root
                color: "brown"
                border.color: "blue"
            }
        }
    ]

    transitions:
        Transition {
            ColorAnimation {
                target: root
//                exclude: border
                property: "color"
                duration: 1000
            }
        }

     MouseArea {
         anchors.fill: parent
         onClicked: root.focus = true
     }

}