Sub MFC()
Dim Dl As Long, L As Long, C As Long
Dim P As Range, R As Range
Application.ScreenUpdating = False
Dl = Cells(Rows.Count, 1).End(xlUp).Row
C = 43
Range("A3:C" & Dl).Interior.ColorIndex = xlNone
Do Until Cells(3 + li, 1) = ""
Set R = Cells(3 + li, 1)
Do While R = R(1 + L, 1)
L = L + 1
Loop
R.Resize(L, 3).Interior.ColorIndex = C
C = IIf(C = 43, xlNone, 43)
li = li + L
L = 0
Loop
End Sub