btn-danger

bootstrap5.css

bootstrap5.css
.btn-danger {
  color: #fff;
  background-color: #dc3545;
  border-color: #dc3545;
}
bootstrap5.css
.btn-danger:hover {
  color: #fff;
  background-color: #bb2d3b;
  border-color: #b02a37;
}
bootstrap5.css
.btn-check:focus + .btn-danger,
.btn-danger:focus {
  color: #fff;
  background-color: #bb2d3b;
  border-color: #b02a37;
  box-shadow: 0 0 0 0.25rem rgba(225, 83, 97, 0.5);
}
bootstrap5.css
.btn-check:checked + .btn-danger,
.btn-check:active + .btn-danger,
.btn-danger:active,
.btn-danger.active,
.show > .btn-danger.dropdown-toggle {
  color: #fff;
  background-color: #b02a37;
  border-color: #a52834;
}
bootstrap5.css
.btn-check:checked + .btn-danger:focus,
.btn-check:active + .btn-danger:focus,
.btn-danger:active:focus,
.btn-danger.active:focus,
.show > .btn-danger.dropdown-toggle:focus {
  box-shadow: 0 0 0 0.25rem rgba(225, 83, 97, 0.5);
}
bootstrap5.css
.btn-danger:disabled,
.btn-danger.disabled {
  color: #fff;
  background-color: #dc3545;
  border-color: #dc3545;
}

html bootstrap5 Sample

ボタンの色:btn-*


  <button type="button" class="btn btn-primary">btn-primary</button>
  <button type="button" class="btn btn-secondary">btn-secondary</button>
  <button type="button" class="btn btn-success">btn-success</button>
  <button type="button" class="btn btn-danger">btn-danger</button>
  <button type="button" class="btn btn-warning">btn-warning</button>
  <button type="button" class="btn btn-info">btn-info</button>
  <button type="button" class="btn btn-light">btn-light</button>
  <button type="button" class="btn btn-dark">btn-dark</button>
  <button type="button" class="btn btn-link">btn-link</button>