public event PivotFieldImageIndexEventHandler FieldValueImageIndex

Public Event FieldValueImageIndex As PivotFieldImageIndexEventHandler

using DevExpress.XtraPivotGrid;

static string[] CategoryNames = new string[] {"Beverages", "Condiments", "Confections", 
  "Dairy Products", "Grains/Cereals", "Meat/Poultry", "Produce", "Seafood"};
public static int GetCategoryIndexByName(object name) {
    if(name != null)
        for(int i = 0; i < CategoryNames.Length; i++)
            if(CategoryNames[i] == name.ToString()) return i;
        return -1;
}

// ...
private void pivotGridControl1_FieldValueImageIndex(object sender, 
  PivotFieldImageIndexEventArgs e) {
    if(e.Field == fieldCategoryName && e.ValueType == PivotGridValueType.Value) 
        e.ImageIndex = GetCategoryIndexByName(e.Value);
    if (e.ValueType == PivotGridValueType.GrandTotal && e.IsColumn == false)
        e.ImageIndex = 8;
}

Imports DevExpress.XtraPivotGrid

Private Shared CategoryNames As String() = New String() {"Beverages", "Condiments", _
  "Confections", "Dairy Products", "Grains/Cereals", "Meat/Poultry", "Produce", "Seafood"}
Public Shared Function GetCategoryIndexByName(ByVal name As Object) As Integer
   If Not name Is Nothing Then
         Dim i As Integer = 0
         While i < CategoryNames.Length
            If CategoryNames(i) = name.ToString() Then
               Return i
            End If
            i += 1
         End While
   End If
   Return -1
End Function
' ...
Private Sub pivotGridControl1_FieldValueImageIndex(ByVal sender As Object, ByVal e As PivotFieldImageIndexEventArgs)
    If e.Field = fieldCategoryName1 AndAlso e.ValueType = PivotGridValueType.Value Then
        e.ImageIndex = GetCategoryIndexByName(e.Value)
    End If
    If e.ValueType = PivotGridValueType.GrandTotal AndAlso e.IsColumn = False Then
        e.ImageIndex = 8
    End If
End Sub