I can change the color of the internal panel , but not the label inside it:
B4X:
Dim item As CLVTreeItem = Tree.AddItem(Tree.Root,$"Item #${i}"$, Null, i)
Dim p As B4XView = item.InternalPanel
p.Color=xui.Color_Magenta
p.GetView(0).SetColorAndBorder(xui.Color_Cyan,4dip,xui.Color_Yellow,5dip) 'Error here: object should first be initialized