Macro to highlight cell based on value in below row

Try:

Sub Highlight()

Dim LR As Long, R As Long

LR = ActiveSheet.Range("A" & ActiveSheet.UsedRange.Rows.Count + 2).End(xlUp).Row

For R = 1 To LR
If Cells(R, 1) <> "" And Cells(R + 1, 1) = "" Then
    With Cells(R, 1).Interior
        .Pattern = xlSolid
        .PatternColorIndex = xlAutomatic
        .Color = 65535
        .TintAndShade = 0
        .PatternTintAndShade = 0
    End With
End If
Next R

End Sub

try this:

Option Explicit

Sub HiLite()
    Dim lr As Long
    Dim i As Long
    lr = Range("A" & Rows.Count).End(xlUp).Row
    
    Application.ScreenUpdating = False
    For i = 1 To lr
    If IsEmpty(Range("A" & i)) Then
        Range("A" & i - 1).Interior.ColorIndex = 37
    End If
    Next i
    Application.ScreenUpdating = True


End Sub

If that takes care of your original question, please select Thread Tools from the menu link above and mark this thread as SOLVED. Thanks for the rep