如何更改下拉按钮的背景色(Vue Bootstrap)

import 'bootstrap/dist/css/bootstrap.css'

<template>
  <div>
    <div class="dropdown">
      <button class="btn btn-primary custom-dropdown-btn" type="button" id="dropdownMenuButton" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
        下拉按钮
      </button>
      <div class="dropdown-menu" aria-labelledby="dropdownMenuButton">
        <!-- 下拉菜单选项 -->
      </div>
    </div>
  </div>
</template>

.custom-dropdown-btn {
  background-color: #ff0000; /* 设置为红色背景 */
}