What is better for reading

Hi all,
first I am a newbie so take note please. I have two treeviews which are filled with .xls files. I am comparing them for any changes but if there are many nodes the application is not responding. Here is my code for better imagination:

'This colors parent nodes in 1st treeview which are in 2nd treeview green and those which are not red 
    Public Sub ColorParent()

        For Each Me.parentnode In TreeView1.Nodes

            FindParent = TreeView2.Nodes.Find(TreeView1.Nodes(parentnode.Index).Name, False)

            On Error Resume Next
            If FindParent.Count = 0 Then

                TreeView1.Nodes(parentnode.Index).BackColor = Color.Red
            Else
                TreeView1.Nodes(FindParent(0).Name).BackColor = Color.Green

            End If

        Next parentnode

    End Sub

'This colors all childs in 1st treeview with childs which are in 2nd treeview at same parents

    Public Sub ColorSameChilds()

        For Each Me.parentnode In TreeView1.Nodes

            For Each Me.parentnode2 In TreeView2.Nodes

                For Each Me.childnodeTV1 In TreeView1.Nodes(parentnode.Index).Nodes

                    For Each Me.childnodeTV2 In TreeView2.Nodes(parentnode2.Index).Nodes

                        FindChild = TreeView2.Nodes(parentnode2.Index).Nodes.Find(TreeView1.Nodes(parentnode.Index).Nodes(childnodeTV1.Index).Name, False)

                        On Error Resume Next
                        If FindChild.Count > 0 Then

                            If TreeView1.Nodes(parentnode.Index).BackColor = Color.Green Then

                                TreeView1.Nodes(parentnode.Index).Nodes(childnodeTV1.Index).BackColor = Color.Green

                            End If
                        End If

                    Next childnodeTV2

                Next childnodeTV1

            Next parentnode2

        Next parentnode

    End Sub

'This just color parents in 1st treeview to orange if there is any uncolored child
    Public Sub ColorDifferentChilds()

        For Each Me.parentnode In TreeView1.Nodes

            For Each Me.childnodeTV1 In TreeView1.Nodes(parentnode.Index).Nodes

                If TreeView1.Nodes(parentnode.Index).BackColor <> Color.Red Then

                    If TreeView1.Nodes(parentnode.Index).Nodes(childnodeTV1.Index).BackColor = Nothing Then

                        TreeView1.Nodes(parentnode.Index).Nodes(childnodeTV1.Index).BackColor = Color.Orange
                        TreeView1.Nodes(parentnode.Index).BackColor = Color.Orange

                    End If
                End If
            Next childnodeTV1

        Next parentnode

    End Sub

The problem is in ColorSameChilds() and I want to ask if there is some faster way how to read data. Can you tell me for example if reading dataset or array is faster then reading treeview. Or can you recommend me any article with sort of these information (useful tips to make fast code). There are about 1k parent nodes in treeview

Thank you