If the coloring is only to help identify the cell during
the time that it is selected see Chip's
RowLiner addin
http://www.cpearson.com/excel/RowLiner.htm

"Chip Pearson"
I would add a safeguard to ensure that Target is only one row tall.

Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Rows.Count = 1 Then
Target.EntireRow.Interior.ColorIndex = 37
Target.Interior.ColorIndex = 8
End If
End Sub