diff --git a/src/app/CentralScene.cpp b/src/app/CentralScene.cpp
index a80e951..faefd85 100644
--- a/src/app/CentralScene.cpp
+++ b/src/app/CentralScene.cpp
@@ -20,7 +20,7 @@ void rebuildCentralScene(geopro::render::Scene& scene, vtkRenderer* renderer,
     scene.clear();
     const bool is2D = (mode == ViewMode::Map2D);
     (void)is2D;
-    // 背景随主题（取 ElaTheme 窗口底色），暗色下不再是刺眼白底。
+    // 背景永远深色（规范§0.5 视图区常深，不随明暗切换），让色阶数据更突出。
     double bgR, bgG, bgB;
     geopro::app::vtkBackground(bgR, bgG, bgB);
     renderer->SetBackground(bgR, bgG, bgB);
diff --git a/src/app/Theme.cpp b/src/app/Theme.cpp
index 3a8b0e1..e052f7f 100644
--- a/src/app/Theme.cpp
+++ b/src/app/Theme.cpp
@@ -668,7 +668,8 @@ QString themed(const QString& designQss)
 
 void vtkBackground(double& r, double& g, double& b)
 {
-    const QColor c = roleColor(isDarkTheme(), "#F4F6FA");
+    // 规范 §0.5/§11：数据画布永远深色，不随明暗切换。取 canvas/bg。
+    const QColor c = tokenColor("canvas/bg");  // #0B1320
     r = c.redF();
     g = c.greenF();
     b = c.blueF();