부트 스트랩 툴팁 화살표 테두리 및 배경색

$(function() {
  $('[data-toggle="tooltip"]').tooltip()
})

.tooltip-main {
  width: 15px;
  height: 15px;
  border-radius: 50%;
  font-weight: 700;
  background: #f3f3f3;
  border: 1px solid #737373;
  color: #737373;
  margin: 4px 121px 0 5px;
  float: right;
  text-align: left !important;
}

.tooltip-qm {
  float: left;
  margin: -2px 0px 3px 4px;
  font-size: 12px;
}

.tooltip-inner {
  max-width: 236px !important;
  height: 76px;
  font-size: 12px;
  padding: 10px 15px 10px 20px;
  background: #FFFFFF;
  color: rgb(0, 0, 0, .7);
  border: 2px solid red;
  text-align: left;
}

.tooltip.show {
  opacity: 1;
}

.bs-tooltip-auto[x-placement^=bottom] .arrow::before,
.bs-tooltip-bottom .arrow::before {
  border-bottom-color: #f00!important;
  /* Red */
}

.bs-tooltip-bottom .arrow::after {
    content: "";
    position: absolute;
    bottom: 0;
    border-width: 0 .4rem .4rem;
    transform: translateY(3px);
    border-color: transparent;
    border-style: solid;
    border-bottom-color: #000;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.bundle.min.js"></script>
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" rel="stylesheet" />
<div class="tooltip-main" data-toggle="tooltip" data-placement="top" data-original-title="Hello world"><span class="tooltip-qm">?</span></div>