<div
        v-for="(color, index) in colors"
        class="colored-box"
        :style="{background: color}"
        @click="sayColor(color)"
        @contextmenu.prevent="$refs.ctx.open($event, {color: color, index: index})">
    </div>

    <context-menu id="testingctx" ref="ctx" @ctx-open="onCtxOpen" @ctx-cancel="resetCtxLocals" @ctx-close="onCtxClose">
      <li class="ctx-header">kkkk</li>
      <li class="ctx-item">option one</li>
      <li class="ctx-item disabled">option two (disabled)</li>
      <li class="ctx-item">add to log</li>
    </context-menu>

Object doesn't support property or method 'open'