diff --git a/common/rhi/yacreader_flow_rhi.cpp b/common/rhi/yacreader_flow_rhi.cpp
index d05c72fa..f6a5e24b 100644
--- a/common/rhi/yacreader_flow_rhi.cpp
+++ b/common/rhi/yacreader_flow_rhi.cpp
@@ -23,7 +23,6 @@ YACReaderFlow3D::YACReaderFlow3D(QWidget *parent, struct Preset p)
       hasBeenInitialized(false),
       backgroundColor(Qt::black),
       textColor(Qt::white),
-      shadingColor(Qt::black),
       flowRightToLeft(false)
 {
     updateCount = 0;
@@ -612,8 +611,6 @@ void YACReaderFlow3D::prepareDrawData(const YACReader3DImageRHI &image, bool isR
     outUniformData.backgroundColor[2] = backgroundColor.blueF();
     outUniformData._pad0 = 0.0f;
 
-    // shadingColor removed from uniform buffer; keep CPU-side shadingColor member intact
-
     outUniformData.reflectionUp = reflectionUp;
     outUniformData.reflectionDown = reflectionBottom;
     outUniformData.isReflection = isReflection ? 1.0f : 0.0f;
@@ -1176,12 +1173,6 @@ void YACReaderFlow3D::setTextColor(const QColor &color)
     update();
 }
 
-void YACReaderFlow3D::setShadingColor(const QColor &color)
-{
-    shadingColor = color;
-    update();
-}
-
 // Event handlers
 void YACReaderFlow3D::wheelEvent(QWheelEvent *event)
 {
diff --git a/common/rhi/yacreader_flow_rhi.h b/common/rhi/yacreader_flow_rhi.h
index 15a61530..387366d7 100644
--- a/common/rhi/yacreader_flow_rhi.h
+++ b/common/rhi/yacreader_flow_rhi.h
@@ -115,11 +115,10 @@ protected:
         float viewProjectionMatrix[16]; // column-major 4x4
         float backgroundColor[3];
         float _pad0; // pad to vec4
-        
         float reflectionUp;
         float reflectionDown;
         float isReflection;
-        float _pad2;
+        float _pad1;
     };
 
     // Pending texture uploads (for async image loading)
@@ -215,7 +214,6 @@ protected:
     /*** Theme Colors ***/
     QColor backgroundColor;
     QColor textColor;
-    QColor shadingColor;
 
     /*** System info ***/
     float viewRotate;
@@ -295,7 +293,6 @@ public slots:
     // Theme color setters
     void setBackgroundColor(const QColor &color);
     void setTextColor(const QColor &color);
-    void setShadingColor(const QColor &color);
 
     virtual void updateImageData() = 0;