Option Explicit
Sub CouleurPlusGrandNombre()
Dim Ws As Worksheet
Dim rep As Variant, lig As Integer, i As Integer
Set Ws = Sheets(1)
With Ws
[B:D].Interior.ColorIndex = xlNone 'Rajouter pour les test
For i = 2 To 4
rep = Application.WorksheetFunction.Max(.Range(.Cells(2, i), .Cells(Rows.Count, i)))
lig = Application.Match(rep, .Range(.Cells(2, i), .Cells(Rows.Count, i)), 0) + 1
.Cells(lig, i).Interior.ColorIndex = 6
Next
End With
End Sub