Sub test()
Dim x$, i&
x = InputBox("tapez p pour pair" & vbCrLf & " i pour impair", "semaine")
Range("A:C").Interior.Color = xlNone
For i = 8 To 373
If x = "p" And Format(CDate(Cells(i, 3).Value), "ww", vbUseSystemDayOfWeek) Mod 2 = 0 Then
Cells(i, 1).Resize(, 3).Interior.Color = vbRed
ElseIf x = "i" And Format(CDate(Cells(i, 3).Value), "ww", vbUseSystemDayOfWeek) Mod 2 <> 0 Then
Cells(i, 1).Resize(, 3).Interior.Color = vbCyan
End If
Next
End Sub