Sub toto()
Dim macol As Byte, x As Byte
Range('A1:H1').Interior.ColorIndex = xlNone
macol = Range('A1').End(xlToRight).Column
Cells(1, macol).Interior.ColorIndex = 3
Cells(1, macol - 1).Interior.ColorIndex = 45
For x = 1 To macol - 2
Cells(1, x).Interior.ColorIndex = 4
Next
End Sub