Gridview ro color change

so for this you need to store the previous rowindex , i suggest you to save data in viewstate check the code

public int selectedroindex
{
 get
 {
    if(ViewState["selectedroindex"]!=null)
      return (int)ViewState["selectedroindex"];
    else 
      return -1;
 }
  set
 {
    ViewState["selectedroindex"]= value;
 }
}

after you do this just restore color back for the previous row before changing selected row color

GridViewRow prevselectedrow = grdRawDevice.Rows[intRowindex];
prevselectedrow.BackColor = System.Drawing.Color.white;//set to orignal colur

int intRowindex) = int.Parse(e.CommandArgument.ToString()) - 1;
            GridViewRow selectedrow = grdRawDevice.Rows[intRowindex];
            selectedrow.BackColor = System.Drawing.Color.Aqua;
            pnlSite.Visible = true;
            hfIndex.Value = intRowindex.ToString();
            lblDeviceID = (Label)grdRawDevice.Rows[intRowindex].FindControl("lbl_deviceID");
            FillData();