How to give cell forecolour in a griedview using two columns warrenty and purchasedate in conditions

<asp:GridView ID="grdEmployeePeripheral" runat="server"
                                    AutoGenerateColumns="False" BackColor="White" BorderColor="#999999"
                                    BorderStyle="None" BorderWidth="1px" CellPadding="3" GridLines="Vertical"
                                    HorizontalAlign="Center"
                                    onrowdatabound="grdEmployeePeripheral_RowDataBound">
                                    <FooterStyle BackColor="#CCCCCC" ForeColor="Black" />
                                    <RowStyle BackColor="#EEEEEE" ForeColor="Black" />
                                    <Columns>

                                        <asp:BoundField DataField="PeripheralType" HeaderText="PeripheralType"
                                            SortExpression="PeripheralType" >
                                            <HeaderStyle HorizontalAlign="Center" />
                                            <ItemStyle HorizontalAlign="Center" />
                                        </asp:BoundField>
                                        <asp:BoundField DataField="Specification" HeaderText="Specification"
                                            SortExpression="Specification" >
                                            <HeaderStyle HorizontalAlign="Center" />
                                            <ItemStyle HorizontalAlign="Center" />
                                        </asp:BoundField>
                                          <asp:BoundField DataField="Remarks" HeaderText="Remarks"
                                            SortExpression="Remarks" >
                                            <HeaderStyle HorizontalAlign="Center" />
                                            <ItemStyle HorizontalAlign="Center" />
                                        </asp:BoundField>
                                          <asp:BoundField DataField="Warrenty" HeaderText="Warrenty"
                                            SortExpression="Warrenty" >
                                            <HeaderStyle HorizontalAlign="Center" />
                                            <ItemStyle HorizontalAlign="Center" />
                                        </asp:BoundField>
                                         <asp:BoundField DataField="PurchaseDate" HeaderText="Purchase Date"
                                            SortExpression="PurchaseDate" DataFormatString="{0:dd-MMM-yyyy}" >
                                            <HeaderStyle HorizontalAlign="Center" />
                                            <ItemStyle HorizontalAlign="Center" />
                                        </asp:BoundField>
                                         <asp:BoundField DataField="PeripheralAssignDate" HeaderText="Peripheral AssignDate"
                                            SortExpression="PeripheralAssignDate" DataFormatString="{0:dd-MMM-yyyy}" >
                                            <HeaderStyle HorizontalAlign="Center" />
                                            <ItemStyle HorizontalAlign="Center" />
                                        </asp:BoundField>

                                    </Columns>
                                    <FooterStyle BackColor="#CCCCCC" ForeColor="Black" />
                                    <PagerStyle BackColor="#999999" ForeColor="Black" HorizontalAlign="Center" />
                                    <SelectedRowStyle BackColor="#008A8C" Font-Bold="True" ForeColor="White" />
                                    <HeaderStyle BackColor="#000084" Font-Bold="True" ForeColor="White" />
                                    <AlternatingRowStyle BackColor="#DCDCDC" />
                                </asp:GridView>