consul/ui/packages/consul-ui/app/components/topology-metrics/skin.scss

.topology-container {
  color: $gray-700;
}

// Columns/Containers & Lines
#downstream-container,
#metrics-container,
#upstream-container {
  border: 1px solid $gray-200;
  border-radius: $decor-radius-100;
}
#downstream-container,
#upstream-container {
  background-color: $gray-100;
}
#downstream-container div:first-child {
  display: inline-flex;
  span::before {
    @extend %with-info-circle-outline-mask, %as-pseudo;
    background-color: $gray-500;
  }
}

// Metrics Container
#metrics-container {
  div:first-child {
    background-color: $white;
  }
  .link {
    background-color: $gray-100;
    a {
      color: $gray-700;
    }
    a::before {
      background-color: $gray-500;
    }
    a:hover {
      color: $color-action;
    }
    .metrics-link::before {
      @extend %with-exit-mask, %as-pseudo;
    }
    .config-link::before {
      @extend %with-docs-mask, %as-pseudo;
    }
  }
}

// SVG Line styling
#downstream-lines svg,
#upstream-lines svg {
  path {
    fill: $transparent;
  }
  circle {
    fill: $white;
  }
  .allow-arrow {
    fill: $gray-300;
    stroke-linejoin: round;
  }
  path,
  .allow-dot,
  .allow-arrow {
    stroke: $gray-300;
    stroke-width: 2;
  }
  path[data-permission='deny'] {
    stroke: $red-500;
  }
  .deny-dot {
    stroke: $red-500;
    stroke-width: 2;
  }
  .deny-arrow {
    fill: $red-500;
    stroke: $red-500;
    stroke-linejoin: round;
  }
}