Private Sub Worksheet_Change(ByVal Target As Range)
If Intersect(Target.Columns, Columns(6)) Is Nothing And Intersect(Target.Columns, Columns(7)) Is Nothing Then Exit Sub
Application.ScreenUpdating = 0: Application.Calculation = Manual
i = Target.Row
For j = 9 To 78
Cells(i, j).Interior.ColorIndex = xlNone
If Cells(4, j).Value >= Cells(i, 6).Value And Cells(4, j).Value <= Cells(i, 7).Value Then Cells(i, j).Interior.ColorIndex = Cells(i, 2).Interior.ColorIndex
Next j
Application.ScreenUpdating = 1: Application.Calculation = xlAutomatic
End Sub