We guess you want to compare  line numbers.
if a line number does not appear in sheet2, color  it red.
Try this

Sub m()
Dim mws As Worksheet
Dim cws As Worksheet

Dim mrng As Range
Dim crng As Range
Dim c As Range

Dim awf As WorksheetFunction
Set awf = Application.WorksheetFunction

Sheets(1).Select
Set mws = Sheets(1)
Set mrng = Range(Cells(2, 2), Cells(2, 2).End(xlDown))

Sheets(2).Select
Set cws = Sheets(2)
Set crng = Range(Cells(2, 2), Cells(2, 2).End(xlDown))

For Each c In mrng
If awf.CountIf(crng, c) <> 1 Then mws.Cells(c.Row, 1).Resize
(1, 6).Interior.Color = vbRed
Next c

Sheets(1).Select
End Sub