Pretty simple idea to change the row color of the GridView control on the onmouseover event.
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
e.Row.Attributes.Add("onmouseover", "this.style.backgroundColor='Silver'");
// This will be the back ground color of the GridView Control
e.Row.Attributes.Add("onmouseout", "this.style.backgroundColor='White'");
}
}