A routine that works specifically with any rowfield selection in a
pivot table. This allows alternating coloring for each row field that
you wish to be colored alternating.
Just select a cell in the label area of the rowfield that you like to
get colored alternating and start ColorRowItemSelectionAlternating()
Adjust the colorindexes to your liking.

Sub ColorRowItemSelectionAlternating()
Dim pf As PivotField
Dim pfits() As PivotItem
Dim r As Range
Dim rAll As Range
Dim c As Range
Dim sw As Boolean
Dim i As Integer

Set r = Selection ' just for restoration at the end of the
formating

Set pf = r.Cells(1).PivotField
If pf Is Nothing Then
MsgBox "Make a cell selection inside a pivot table and try
again!"
Else
pf.Parent.PivotSelect "'" & pf.Name & "'[All]", xlLabelOnly,
True
Set rAll = Selection
i = 1
ReDim Preserve pfits(i)
Set pfits(1) = rAll.Cells(1).PivotItem ' store pivotitems in
array with same order as on worksheet
For Each c In rAll
If c.PivotItem.Name < pfits(i).Name Then
i = i + 1
ReDim Preserve pfits(i)
Set pfits(i) = c.PivotItem
End If
Next c

For i = LBound(pfits) To UBound(pfits) ' lets color them
alternating
If Not PivotItemSelect(pf, pfits(i), xlLabelOnly) Is
Nothing Then ' change mode to xlDataAndLabel if you like to color
the data too.
If sw Then
Selection.Interior.ColorIndex = 35
Else
Selection.Interior.ColorIndex = 34
End If
sw = Not sw
End If
Next i
End If
r.Select
End Sub

Function PivotItemSelect(pf As PivotField, pfit As PivotItem, mode As
XlPTSelectionMode) As Range
err.Clear
On Error Resume Next
pfit.Parent.Parent.PivotSelect "'" & pf.Name & "'[" & pfit.Name &
"]", mode, True
If err.Number < 0 Then
Set PivotItemSelect = Nothing
Else
Set PivotItemSelect = Selection
If mode = xlLabelOnly And (pf.Subtotals(1) = True Or
pf.Subtotals(2) = True) Then
pfit.Parent.Parent.PivotSelect "'" & pf.Name & "'[" &
pfit.Name & "]", xlDataAndLabel, True
Range(Cells(Selection.Row + Selection.Rows.Count,
Selection.Column), _
Cells(Selection.Row + Selection.Rows.Count, _
Selection.Areas(Selection.Areas.Count).Column
+ Selection.Areas(Selection.Areas.Count).Columns.Cou nt - 1)).Select
Set PivotItemSelect = Union(PivotItemSelect, Selection)
PivotItemSelect.Select
End If
End If
err.Clear
On Error GoTo 0
End Function