superset-frontend/packages/superset-ui-demo/storybook/stories/superset-ui-color/color-styles.css

.palette-label {
  margin: 4px 12px 4px 0;
}

.palette-container {
  display: flex;
  flex-direction: row;
  border: 1px solid #eaeaea;
  width: fit-content;
}

.palette-item {
  width: 16px;
  height: 16px;
}