aşağıdaki kodu dener mısiniz
hücre içeriği değiştiğinde çalışır

Private Sub Worksheet_Change(ByVal Target As Range)

Dim Kolon() As String

Dim xStun As Range

Dim Hcr As Range

Set xStun = Range("A1:AE1")



'If Not Application.Intersect(xStun, Range(Target.Address)) Is Nothing Then

    

For Each Hcr In xStun

Kolon = Split(Hcr.Address, "$")

If Weekday(Hcr.Value, 0) = 7 Then Range(Kolon(1) & ":" & Kolon(1)).Interior.ColorIndex = 4 Else Hcr.Columns(Hcr.Column).Interior.ColorIndex = 0

Next Hcr



End Sub