lottery/resources/scss/vue/bootstrap-vue/_validation.scss

// reason: contextual states
// valid state
.custom-control-input.is-valid {
  &:not(:disabled):active {
    ~ .custom-control-label::before {
      background-color: $success;
      border-color: $success;
    }
  }
}
// invalid state
.custom-control-input.is-invalid {
  &:not(:disabled):active {
    ~ .custom-control-label::before {
      background-color: $danger;
      border-color: $danger;
    }
  }
}