Puedes usar el ItemDataBound de tu grid....
sería algo así:
Cita: Sub DataGrid1_ItemDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DataGridItemEventArgs)
If e.Item.ItemType = ListItemType.AlternatingItem Or _
e.Item.ItemType = ListItemType.Item Then
e.Item.Attributes.Add("onmouseover", "this.style.backgroundColor='red'")
e.Item.Attributes.Add("onmouseout", "this.style.backgroundColor='white'")
End If
End Sub
Salu2