MarkAlternateRowslnColour

Sub MarkAlternateRowslnColour()

With ActiveSheet
CC = .Range("AZl").End(xlToLeft).Column
RR -.Range("A50000").End(xlUp).Row
DD = .Range("Al").Resize(RR, 1)
clr = RGB(179, 235, 255)
clrx = ""
For rdx = 3 To UBound(DD)
If DD(rdx, 1) <> DD(rdx - 1, 1) Then
If clrx = clr Then
clrx = ""
Else
clrx = clr
End If
End If
If clrx <> "" Then
.Range("a" & rdx).Resize(l, CC).lnterior.Color = clrx
Next rdx
End With
End Sub