<div class="bg-primary text-white">Primary<a href="/" class="btn btn-primary">asdf</a></div>

:root {
  --bs-primary: #6610f2;
  --bs-primary-rgb: 102, 16, 242;
}

.demo {
  width: 100%;
  height: 100vh;
  display: flex;
  flex-direction: column;
  > div {
    flex-grow: 1;
    display: flex;
    justify-content: center;
    align-items: center;
  }
}