Keenthemes Iconsicons can be used as through class names as shown below.
                        <i class="ki ki-plus"></i>
                        <i class="ki ki-arrow-up"></i>
                        <i class="ki ki-round"></i>
                        <i class="ki ki-reload"></i>
                        <i class="ki ki-refresh"></i>
                        <i class="ki ki-solid-plus"></i>
                        
														Use
													.icon-{color}class format to set different colors.
                        <i class="ki ki-plus text-success"></i>
                        <i class="ki ki-arrow-up text-primary"></i>
                        <i class="ki ki-round text-danger"></i>
                        <i class="ki ki-reload text-warning"></i>
                        <i class="ki ki-refresh text-info"></i>
                        <i class="ki ki-solid-plus text-dark"></i>
                        
														Use
													.icon-{size}class format to set different sizes.
                        <i class="ki ki-solid-plus icon-xs"></i>
                        <i class="ki ki-solid-plus icon-sm"></i>
                        <i class="ki ki-solid-plus icon-md"></i>
                        <i class="ki ki-solid-plus icon-lg"></i>
                        <i class="ki ki-solid-plus icon-xl"></i>
                        <i class="ki ki-solid-plus icon-2x"></i>
                        <i class="ki ki-solid-plus icon-3x"></i>
                        <i class="ki ki-solid-plus icon-4x"></i>
                        <i class="ki ki-solid-plus icon-5x"></i>
                        <i class="ki ki-solid-plus icon-6x"></i>
                        <i class="ki ki-solid-plus icon-7x"></i>
                        <i class="ki ki-solid-plus icon-8x"></i>
                        <i class="ki ki-solid-plus icon-9x"></i>
                        <i class="ki ki-solid-plus icon-10x"></i>
                        
														You can use KeenthemesIcons literally with any element within Metronic.
                        <a href="#" class="btn btn-success font-weight-bold mr-2">
                            <i class="ki ki-plus icon-sm"></i> Button example
                        </a>
                        <a href="#" class="btn btn-light-danger font-weight-bold mr-2">
                            <i class="ki ki-bold-close icon-sm"></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="ki ki-outline-info icon-md"></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="ki ki-gear 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="ki ki-info 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="ki ki-wrench 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>