Option Explicit
Sub ColourDuplicates()
'Based on Fluff's code from here: _
https://www.mrexcel.com/forum/excel-questions/1037008-find-duplicate-rows-multiple-cells-2.html#post4980293
Dim Valu As String
Dim Cl As Range
Dim UsdCols As Long
Application.ScreenUpdating = False
'Create an unique array of entries in Sheet2
UsdCols = Sheets("Sheet2").Cells(1, Columns.Count).End(xlToLeft).Column
With CreateObject("scripting.dictionary")
For Each Cl In Sheets("Sheet2").Range("A1", Sheets("Sheet2").Range("A" & Rows.Count).End(xlUp)) 'Starts from cell A1 and works dows Col. A in Sheet2. Change to suit if necessary.
Valu = Join(Application.Transpose(Application.Transpose(Cl.Resize(, UsdCols))))
If Not .exists(Valu) Then
.Add Valu, Cl.Resize(, UsdCols)
End If
Next Cl
'Now use the this array to check the entries in Sheet1 and if they're in the array highlight the entries in green (change to suit if necessary)
UsdCols = Sheets("Sheet1").Cells(1, Columns.Count).End(xlToLeft).Column
For Each Cl In Sheets("Sheet1").Range("A1", Sheets("Sheet1").Range("A" & Rows.Count).End(xlUp)) 'Starts from cell A1 and works dows Col. A in Sheet1. Change to suit if necessary.
Valu = Join(Application.Transpose(Application.Transpose(Cl.Resize(, UsdCols))))
If .exists(Valu) Then
Cl.Resize(, UsdCols).Interior.Color = RGB(0, 255, 0)
Else
Cl.Resize(, UsdCols).Interior.Color = xlNone
End If
Next Cl
End With
Application.ScreenUpdating = True
End Sub