diff --git a/gui/GraphEditorWidget.cpp b/gui/GraphEditorWidget.cpp
index 108e8b7..9470e1f 100644
--- a/gui/GraphEditorWidget.cpp
+++ b/gui/GraphEditorWidget.cpp
@@ -1668,16 +1668,23 @@ void GraphEditorWidget::updateMeters() {
     m_masterMeterR->setLevel(master.value.peak_right);
   }
 
+  bool anyActive = false;
   for (auto &[nodeId, row] : m_nodeMeters) {
     const WarpNodeData *data = m_model->warpNodeData(nodeId);
     if (!data || !row.meter)
       continue;
     auto peak = m_client->NodeMeterPeak(data->info.id);
     if (peak.ok()) {
-      row.meter->setLevel(
-          std::max(peak.value.peak_left, peak.value.peak_right));
+      float level = std::max(peak.value.peak_left, peak.value.peak_right);
+      row.meter->setLevel(level);
+      m_model->setNodePeakLevel(nodeId, level);
+      if (level > 0.001f)
+        anyActive = true;
     }
   }
+
+  if (anyActive && m_scene)
+    m_scene->update();
 }
 
 void GraphEditorWidget::rebuildNodeMeters() {
diff --git a/gui/SquareConnectionPainter.cpp b/gui/SquareConnectionPainter.cpp
index ffa09b4..57739e1 100644
--- a/gui/SquareConnectionPainter.cpp
+++ b/gui/SquareConnectionPainter.cpp
@@ -1,4 +1,5 @@
 #include "SquareConnectionPainter.h"
+#include "WarpGraphModel.h"
 
 #include <QtNodes/internal/BasicGraphicsScene.hpp>
 #include <QtNodes/internal/ConnectionGraphicsObject.hpp>
@@ -187,6 +188,30 @@ void SquareConnectionPainter::paint(
 
   auto path = orthogonalPath(cgo);
 
+  float peakLevel = 0.0f;
+  auto *scene = cgo.nodeScene();
+  if (scene) {
+    auto *model = dynamic_cast<WarpGraphModel *>(&scene->graphModel());
+    if (model) {
+      auto cId = cgo.connectionId();
+      peakLevel = std::max(model->nodePeakLevel(cId.outNodeId),
+                           model->nodePeakLevel(cId.inNodeId));
+    }
+  }
+
+  auto activeColor = [&](QColor base) -> QColor {
+    if (peakLevel < 0.005f)
+      return base;
+    float t = std::min(peakLevel * 2.0f, 1.0f);
+    int r = static_cast<int>(base.red() + t * (60 - base.red()));
+    int g = static_cast<int>(base.green() + t * (210 - base.green()));
+    int b = static_cast<int>(base.blue() + t * (80 - base.blue()));
+    return QColor(std::clamp(r, 0, 255),
+                  std::clamp(g, 0, 255),
+                  std::clamp(b, 0, 255),
+                  base.alpha());
+  };
+
   if (hovered || selected) {
     QPen pen;
     pen.setWidth(static_cast<int>(2 * style.lineWidth()));
@@ -205,9 +230,15 @@ void SquareConnectionPainter::paint(
     painter->setBrush(Qt::NoBrush);
     painter->drawPath(path);
   } else {
+    QColor base = selected ? style.selectedColor() : style.normalColor();
+    QColor color = selected ? base : activeColor(base);
+    float width = style.lineWidth();
+    if (!selected && peakLevel > 0.005f)
+      width += peakLevel * 1.5f;
+
     QPen pen;
-    pen.setWidth(style.lineWidth());
-    pen.setColor(selected ? style.selectedColor() : style.normalColor());
+    pen.setWidthF(width);
+    pen.setColor(color);
     painter->setPen(pen);
     painter->setBrush(Qt::NoBrush);
     painter->drawPath(path);
diff --git a/gui/WarpGraphModel.cpp b/gui/WarpGraphModel.cpp
index 03d1679..682ff9f 100644
--- a/gui/WarpGraphModel.cpp
+++ b/gui/WarpGraphModel.cpp
@@ -965,6 +965,17 @@ WarpGraphModel::nodeVolumeState(QtNodes::NodeId nodeId) const {
   return {};
 }
 
+void WarpGraphModel::setNodePeakLevel(QtNodes::NodeId nodeId, float level) {
+  constexpr float kDecay = 0.82f;
+  float &stored = m_peakLevels[nodeId];
+  stored = std::max(level, stored * kDecay);
+}
+
+float WarpGraphModel::nodePeakLevel(QtNodes::NodeId nodeId) const {
+  auto it = m_peakLevels.find(nodeId);
+  return it != m_peakLevels.end() ? it->second : 0.0f;
+}
+
 void WarpGraphModel::saveLayout(const QString &path) const {
   ViewState vs{};
   saveLayout(path, vs);
diff --git a/gui/WarpGraphModel.h b/gui/WarpGraphModel.h
index 7c09ca4..aa76c3a 100644
--- a/gui/WarpGraphModel.h
+++ b/gui/WarpGraphModel.h
@@ -95,6 +95,9 @@ public:
   void setNodeVolumeState(QtNodes::NodeId nodeId, const NodeVolumeState &state);
   NodeVolumeState nodeVolumeState(QtNodes::NodeId nodeId) const;
 
+  void setNodePeakLevel(QtNodes::NodeId nodeId, float level);
+  float nodePeakLevel(QtNodes::NodeId nodeId) const;
+
 Q_SIGNALS:
   void beginBatchUpdate();
   void endBatchUpdate();
@@ -169,4 +172,5 @@ private:
   std::unordered_map<QtNodes::NodeId, NodeVolumeState> m_volumeStates;
   std::unordered_map<QtNodes::NodeId, QPointer<QWidget>> m_volumeWidgets;
   mutable std::unordered_map<QtNodes::NodeId, QVariant> m_styleCache;
+  std::unordered_map<QtNodes::NodeId, float> m_peakLevels;
 };