color_field_widget_grid.css in Color Field 8.2

.simpleColorChooser {
  z-index: 1;
  max-width: 100%;
}

.js-color-field-widget-grid__color.required {
  display: block !important;
  width: 0;
  height: 0;
  padding: 0;
  border: none;
  overflow: hidden;
}