Cells.Select
Range("A1").Activate
Selection.FormatConditions.Delete
Selection.FormatConditions.Add Type:=xlExpression, Formula1:= _
"=(COLONNE()>=32)*(A$1<>"""")*MOD(ENT((COLONNE()-32)/3);2)"
Selection.FormatConditions(1).Interior.ColorIndex = 37 'couleur à adapter
Selection.FormatConditions.Add Type:=xlExpression, Formula1:= _
"=(COLONNE()>=32)*(A$1<>"""")*NON(MOD(ENT((COLONNE()-32)/3);2))"
Selection.FormatConditions(2).Interior.ColorIndex = 40 'couleur à adapter
Range("A1").Select