MS Excel: Highlight similar duplicates with similar colors

I had 10 independent SQL tables with no relationships.Each table contained around 20-30 columns each. I needed to establish relation between the tables. So quickly I pasted the columns in to an excel sheet and ran this macro to highlight duplicates, meaning same column availability in all columns.

Sub Highlight_Duplicates()
    Dim ws As Worksheet
    Dim cell As Range
    Dim myrng As Range
    Dim clr As Long
    Dim lastCell As Range

    Set ws = ThisWorkbook.Sheets("Sheet1")
    Set myrng = ws.Range("A2:K" & Range("A" & ws.Rows.Count).End(xlUp).Row)
    With myrng
        Set lastCell = .Cells(.Cells.Count)
    End With
    myrng.Interior.ColorIndex = xlNone
    clr = 3

    For Each cell In myrng
        If Application.WorksheetFunction.CountIf(myrng, cell) > 1 Then
            ' addresses will match for first instance of value in range
            If myrng.Find(what:=cell, lookat:=xlWhole, MatchCase:=False, after:=lastCell).Address = cell.Address Then
                ' set the color for this value (will be used throughout the range)
                cell.Interior.ColorIndex = clr
                clr = clr + 1
            Else
                ' if not the first instance, set color to match the first instance
                cell.Interior.ColorIndex = myrng.Find(what:=cell, lookat:=xlWhole, MatchCase:=False, after:=lastCell).Interior.ColorIndex
            End If
        End If
    Next
End Sub

Below is the depicted sample executed macro excel sheet. Ignore first row as they are just headers. The macro executes from second row.