Flaticonicons can be used as through class names as shown below.
                        <i class="flaticon2-bell-4"></i>
                        <i class="flaticon2-gear"></i>
                        <i class="flaticon2-pen"></i>
                        <i class="flaticon2-open-box"></i>
                        <i class="flaticon2-hourglass-1"></i>
                        <i class="flaticon2-graph-1"></i>
                        
														Use
													.icon-{color}class format to set different colors.
                        <i class="flaticon2-bell-4 text-success"></i>
                        <i class="flaticon2-gear text-primary"></i>
                        <i class="flaticon2-pen text-danger"></i>
                        <i class="flaticon2-open-box text-warning"></i>
                        <i class="flaticon2-hourglass-1 text-info"></i>
                        <i class="flaticon2-graph-1 text-dark"></i>
                        
														Use
													.icon-{size}class format to set different sizes.
                        <i class="flaticon2-hourglass-1 icon-xs"></i>
                        <i class="flaticon2-hourglass-1 icon-sm"></i>
                        <i class="flaticon2-hourglass-1 icon-md"></i>
                        <i class="flaticon2-hourglass-1 icon-lg"></i>
                        <i class="flaticon2-hourglass-1 icon-xl"></i>
                        <i class="flaticon2-hourglass-1 icon-2x"></i>
                        <i class="flaticon2-hourglass-1 icon-3x"></i>
                        <i class="flaticon2-hourglass-1 icon-4x"></i>
                        <i class="flaticon2-hourglass-1 icon-5x"></i>
                        <i class="flaticon2-hourglass-1 icon-6x"></i>
                        <i class="flaticon2-hourglass-1 icon-7x"></i>
                        <i class="flaticon2-hourglass-1 icon-8x"></i>
                        <i class="flaticon2-hourglass-1 icon-9x"></i>
                        <i class="flaticon2-hourglass-1 icon-10x"></i>
                        
														You can use Flaticons literally with any element within Metronic.
                        <a href="#" class="btn btn-success font-weight-bold mr-2">
                            <i class="flaticon2-bell-4"></i> Button example
                        </a>
                        <a href="#" class="btn btn-light-danger font-weight-bold mr-2">
                            <i class="flaticon2-open-box"></i> Button example 2
                        </a>
                        <div class="dropdown dropdown-inline">
                            <a href="#" class="btn btn-light-primary font-weight-bold dropdown-toggle" data-toggle="dropdown" aria-expanded="false">
                                <i class="flaticon2-graph-1"></i> Dropdown example
                            </a>
                            <div class="dropdown-menu dropdown-menu-md py-5">
                                <ul class="navi navi-hover">
                                    <li class="navi-item">
                                        <a class="navi-link" href="#">
                                            <span class="navi-icon"><i class="flaticon2-analytics text-danger"></i></span>
                                            <span class="navi-text">Messages</span>
                                            <span class="label label-light-danger font-weight-bold label-inline">new</span>
                                        </a>
                                    </li>
                                    <li class="navi-item">
                                        <a class="navi-link" href="#">
                                            <span class="navi-icon"><i class="flaticon2-pie-chart-2  text-warning"></i></span>
                                            <span class="navi-text">Settings</span>
                                        </a>
                                    </li>
                                    <li class="navi-item">
                                        <a class="navi-link" href="#">
                                            <span class="navi-icon"><i class="flaticon2-box-1  text-success"></i></span>
                                            <span class="navi-text">Tasks</span>
                                            <span class="navi-label">
                                                <span class="label label-warning label-rounded">5</span>
                                            </span>
                                        </a>
                                    </li>
                                    <li class="navi-item">
                                        <a class="navi-link" href="#">
                                            <span class="navi-icon"><i class="flaticon2-file  text-primary"></i></span>
                                            <span class="navi-text">Orders</span>
                                        </a>
                                    </li>
                                </ul>
                            </div>
                        </div>