diff --git a/Codex Documentation/Current Software Plan/V1_BLOCK_04_Backlog_Quick_Capture.md b/Codex Documentation/Archived plans/V1_BLOCK_04_Backlog_Quick_Capture.md
similarity index 89%
rename from Codex Documentation/Current Software Plan/V1_BLOCK_04_Backlog_Quick_Capture.md
rename to Codex Documentation/Archived plans/V1_BLOCK_04_Backlog_Quick_Capture.md
index 3d0f09e..aad3549 100644
--- a/Codex Documentation/Current Software Plan/V1_BLOCK_04_Backlog_Quick_Capture.md	
+++ b/Codex Documentation/Archived plans/V1_BLOCK_04_Backlog_Quick_Capture.md	
@@ -1,6 +1,6 @@
 # V1 Block 04 — Backlog and Quick Capture
 
-Status: Planned
+Status: Completed
 
 Purpose: Support low-friction task capture and a unified backlog/wishlist model.
 
@@ -116,6 +116,8 @@ BREAKPOINT: Stop here. Confirm `high` mode before implementing scheduling integr
 
 Recommended Codex level: low
 
+Status: Completed
+
 Tasks:
 
 Implement age/staleness calculation for backlog display:
@@ -130,6 +132,15 @@ Acceptance criteria:
 
 - Tests cover fresh, aging, stale, and configurable thresholds.
 
+Execution notes:
+
+- Added `BacklogStalenessMarker` values for green, blue, and purple display buckets.
+- Added `BacklogStalenessSettings` with configurable green and blue thresholds.
+- Added `BacklogView.stalenessMarkerFor` to calculate display marker state without side effects or prompts.
+- Default thresholds are green through 7 days, blue through 30 days, and purple from 31 days onward.
+- Added tests for fresh, aging, stale, and custom threshold behavior.
+- `dart analyze` and `dart test` passed.
+
 Commit suggestion:
 
 ```text
diff --git a/lib/src/backlog.dart b/lib/src/backlog.dart
index a8b62f4..0a3cef5 100644
--- a/lib/src/backlog.dart
+++ b/lib/src/backlog.dart
@@ -19,17 +19,54 @@ enum BacklogSortKey {
   timesPushed,
 }
 
+/// Visual age bucket for backlog display.
+enum BacklogStalenessMarker {
+  green,
+  blue,
+  purple,
+}
+
+/// Configurable thresholds for backlog age markers.
+class BacklogStalenessSettings {
+  const BacklogStalenessSettings({
+    this.greenMaxAge = const Duration(days: 7),
+    this.blueMaxAge = const Duration(days: 30),
+  });
+
+  final Duration greenMaxAge;
+  final Duration blueMaxAge;
+
+  BacklogStalenessMarker markerFor({
+    required Task task,
+    required DateTime now,
+  }) {
+    final age = now.difference(task.createdAt);
+
+    if (age <= greenMaxAge) {
+      return BacklogStalenessMarker.green;
+    }
+
+    if (age <= blueMaxAge) {
+      return BacklogStalenessMarker.blue;
+    }
+
+    return BacklogStalenessMarker.purple;
+  }
+}
+
 /// Read-only backlog projection over the unified task list.
 class BacklogView {
   const BacklogView({
     required this.tasks,
     required this.now,
     this.staleAfter = const Duration(days: 31),
+    this.stalenessSettings = const BacklogStalenessSettings(),
   });
 
   final List<Task> tasks;
   final DateTime now;
   final Duration staleAfter;
+  final BacklogStalenessSettings stalenessSettings;
 
   List<Task> get backlogTasks {
     return tasks.where((task) => task.isBacklog).toList(growable: false);
@@ -48,6 +85,10 @@ class BacklogView {
     return List<Task>.unmodifiable(sortedTasks);
   }
 
+  BacklogStalenessMarker stalenessMarkerFor(Task task) {
+    return stalenessSettings.markerFor(task: task, now: now);
+  }
+
   bool _matchesFilter(Task task, BacklogFilter filter) {
     return switch (filter) {
       BacklogFilter.inbox => task.projectId == 'inbox',
diff --git a/test/scheduling_engine_test.dart b/test/scheduling_engine_test.dart
index 7660373..ea6b703 100644
--- a/test/scheduling_engine_test.dart
+++ b/test/scheduling_engine_test.dart
@@ -216,6 +216,47 @@ void main() {
       ]);
     });
 
+    test('backlog staleness markers cover default thresholds', () {
+      final fresh = Task.quickCapture(
+        id: 'fresh',
+        title: 'Fresh',
+        createdAt: now.subtract(const Duration(days: 7)),
+      );
+      final aging = Task.quickCapture(
+        id: 'aging',
+        title: 'Aging',
+        createdAt: now.subtract(const Duration(days: 8)),
+      );
+      final stale = Task.quickCapture(
+        id: 'stale',
+        title: 'Stale',
+        createdAt: now.subtract(const Duration(days: 31)),
+      );
+      final view = BacklogView(tasks: [fresh, aging, stale], now: now);
+
+      expect(view.stalenessMarkerFor(fresh), BacklogStalenessMarker.green);
+      expect(view.stalenessMarkerFor(aging), BacklogStalenessMarker.blue);
+      expect(view.stalenessMarkerFor(stale), BacklogStalenessMarker.purple);
+    });
+
+    test('backlog staleness markers support configurable thresholds', () {
+      final task = Task.quickCapture(
+        id: 'custom',
+        title: 'Custom',
+        createdAt: now.subtract(const Duration(days: 5)),
+      );
+      final view = BacklogView(
+        tasks: [task],
+        now: now,
+        stalenessSettings: const BacklogStalenessSettings(
+          greenMaxAge: Duration(days: 2),
+          blueMaxAge: Duration(days: 4),
+        ),
+      );
+
+      expect(view.stalenessMarkerFor(task), BacklogStalenessMarker.purple);
+    });
+
     test('unchecked quick capture goes to backlog', () {
       const service = QuickCaptureService();