Problème dans boucle if

Sub Bouton14_QuandClic()

Dim dercol3 As Byte
Dim derline3 As Byte
dercol3 = Range("B4").End(xlToRight).Column
derline3 = Range("B4").End(xlDown).Row

Dim k As Byte
For k = 6 To dercol3 - 1

If Cells(4, k).Value < 0 Then
Cells(4, k).Select
    With Selection.Interior
        .ColorIndex = 35
        .Pattern = xlSolid
    End With

        ElseIf Cells(4, k).Value > 0 Then
        If Cells(4, k).Value < 10 Then
        Cells(4, k).Select
            With Selection.Interior
                .ColorIndex = 6
                .Pattern = xlSolid
            End With

                ElseIf Cells(4, k).Value > 10 Then
                    If Cells(4, k).Value < 20 Then
                    Cells(4, k).Select
                        With Selection.Interior
                            .ColorIndex = 44
                            .Pattern = xlSolid
                        End With

                            ElseIf Cells(4, k).Value > 20 Then
                            If Cells(4, k).Value < 50 Then
                            Cells(4, k).Select
                                With Selection.Interior
                                    .ColorIndex = 45
                                    .Pattern = xlSolid

                                        ElseIf Cells(4, k).Value > 50 Then
                                        Cells(4, k).Select
                                            With Selection.Interior
                                                .ColorIndex = 46
                                                .Pattern = xlSolid
                                            End With

                            End If
                    End If
         End If
End If