bootstrap/docs/assets/scss/_buttons.scss

// Buttons
//
// Custom buttons for the docs.

.btn-bs {
  color: $bd-purple-bright;
  border-color: $bd-purple-bright;

  &:hover,
  &:focus,
  &:active {
    color: #fff;
    background-color:$bd-purple-bright;
    border-color: $bd-purple-bright;
  }
}