Experimente esta pequena macro:
Sub ShadyRow()
Dim s1 As Worksheet, s2 As Worksheet, N As Long
Dim i As Long
Set s1 = Sheets("Sheet1")
Set s2 = Sheets("Sheet2")
N = s1.Cells(Rows.Count, "A").End(xlUp).Row
For i = 1 To N
If s1.Cells(i, "A").Value = "X" Then
s2.Cells(i, "A").EntireRow.Interior.Color = RGB(100, 100, 100)
End If
Next i
End Sub