element Tooltip背景颜色样式修改

<el-tooltip content="Top center" placement="top" popper-class="atooltip">
  <el-button>Dark</el-button>
</el-tooltip>

css修改

.atooltip.el-tooltip__popper[x-placement^="top"] .popper__arrow {
  border-top-color: pink;
}
.atooltip.el-tooltip__popper[x-placement^="top"] .popper__arrow:after {
  border-top-color: pink;
}
.atooltip {
  background: pink !important;
}