Your RowDataBound
Event should like this
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
if (e.Row.Cells[0].Text == "open")
{
e.Row.Cells[0].ForeColor = System.Drawing.Color.Red;
}
else if (e.Row.Cells[0].Text == "close")
{
e.Row.Cells[0].ForeColor = System.Drawing.Color.Black;
}
else
{
e.Row.Cells[0].ForeColor = System.Drawing.Color.Green;
}
}
}