Option Explicit
Option Compare Text
Private Sub Worksheet_Change(ByVal Target As Range)
Dim c As Range, f As Worksheet, txto As String, txtc As String, doublon As Boolean
doublon = False
If Not Intersect(Target, [B5:F10]) Is Nothing And Not IsEmpty(Target) And Target.Row <> 8 Then
For Each c In Target.Cells
txto = Right(c, Len(c) - InStr(1, c, Chr(10)))
For Each f In ThisWorkbook.Sheets
txtc = f.Cells(c.Row, c.Column)
If ActiveSheet.Name <> f.Name And Len(Trim(txtc)) <> 0 And Right(txtc, Len(txtc) - InStr(1, txtc, Chr(10))) = txto Then
f.Cells(c.Row, c.Column).Interior.Color = 65535
Target.Interior.Color = 65535
doublon = True
Else
f.Cells(c.Row, c.Column).Interior.Color = [BX1000000].Interior.Color
If Not doublon Then Target.Interior.Color = [BX1000000].Interior.Color
End If
Next f
Next c
End If
End Sub