papercss/src/components/_badges.scss

.badge {
  @include border-style();
  @include color('color', 'white');
  @include color('background-color', 'muted');
  @include color('border-color', 'primary');
  border: 2px solid;
  border-color: transparent;
  display: inline-block;
  font-size: 75%;
  font-weight: 700;
  line-height: 1;
  padding: 0.25em 0.4em;
  text-align: center;
  vertical-align: baseline;
  white-space: nowrap;
}

@each $colorName, $color in $colors {
  .badge.#{$colorName} {
    @include color('background-color', #{$colorName});
  }
}