@salesforce-ux/design-system/css/popovers/error/index.css

Salesforce Lightning Design System

/*! Lightning Design System 2.12.0 */
@charset "UTF-8";
.slds-popover_error .slds-popover__header {
  background-color: #c23934;
  color: white;
}
.slds-popover_error.slds-nubbin_top:before,
.slds-popover_error.slds-nubbin_top-left:before,
.slds-popover_error.slds-nubbin_top-right:before,
.slds-popover_error.slds-nubbin_left-top:before,
.slds-popover_error.slds-nubbin_right-top:before {
  background-color: #c23934;
}

.slds-popover_error,
.slds-popover_warning {
}
.slds-popover_error .slds-popover__header,
.slds-popover_warning .slds-popover__header {
  border-radius: calc(0.25rem - 1px) calc(0.25rem - 1px) 0 0;
}
.slds-popover_error .slds-popover__body_scrollable,
.slds-popover_warning .slds-popover__body_scrollable {
  max-height: 150px;
  overflow-y: auto;
  border-bottom: 1px solid #dddbda;
}
.slds-popover_error .slds-popover__body_scrollable + .slds-popover__footer,
.slds-popover_warning .slds-popover__body_scrollable + .slds-popover__footer {
  border-top: 0;
}