Modify TreeViewItems - Does not change visually

Hi.

I have this treeview, programatically created (adding the nodes)

When each child nodes OPC-Tag changes, (it comes with 1 or 0).
The OPC-Tag comes in just nicely.

And each time the tags updates i call this function

        private void UpdateStatuses(string strTag, string sStatus)
        {
            foreach (Thing tvi in tv.Items)
            {
                bool bRed = false;
                foreach (Thing tva in tvi.Children)
                {
                    if (tva.Tag == strTag)
                    {
                        if (sStatus == "0")
                        {
                            tva.StatusBrush = new SolidColorBrush(Colors.Red);
                            tva.Name = strTag;
                            bRed = true;
                        }
                        else
                        {
                            tva.StatusBrush = new SolidColorBrush(Colors.Green);
                        }
                    }
                }
                tb3.Text = "\nRed: " + bRed;
                if (bRed)
                {
                    tvi.StatusBrush = new SolidColorBrush(Colors.Red);
                }
                else
                {
                    tvi.StatusBrush = new SolidColorBrush(Colors.Green);
                }
            }
            tv.ExpandAll();
        }

But the Illipse does not change the color, and where i try to change the

tva.Name = strTag;

The child node still have the old name.

What i am trying to accomplis is

* Reflect the color of each node according to the tag value
* Update the parent node so, if any listed node is not green, the parent node should be red, else be green.

Each item is this class

    public class Thing
    {
        public SolidColorBrush StatusBrush { get; set; }
        public string Name { get; set; }
        public string Tag { get; set; }
        public ObservableCollection<Thing> Children { get; set; }
    }