Sub Test()
    Dim MyName As String
    Dim ColorOn As Boolean
    Dim Lastrow As Integer, i As Integer
    
    'Initalise variables
    ColorOn = True
    Lastrow = Range("A" & Rows.Count).End(xlUp).Row
    
    'Start Loop
    For i = 2 To Lastrow
        MyName = Range("A" & i - 1).Formula
        'check for duplicate entries
        If Range("A" & i).Formula = MyName Then
            'choose same color as cell above
            Range("A" & i).Range("A1:C1").Interior.ColorIndex = Range("A" & i - 1).Interior.ColorIndex
        Else
            'switch color
            ColorOn = Not ColorOn
            If ColorOn = True Then
                'First Three coloumns coloured
                Range("A" & i).Range("A1:C1").Interior.ColorIndex = 15
            End If
        End If
     Next i
            
End Sub