diff --git a/lib/GfxRenderer/GfxRenderer.cpp b/lib/GfxRenderer/GfxRenderer.cpp
index 707fcbd..c6a7cc3 100644
--- a/lib/GfxRenderer/GfxRenderer.cpp
+++ b/lib/GfxRenderer/GfxRenderer.cpp
@@ -162,8 +162,14 @@ int GfxRenderer::getLineHeight(const int fontId) const {
   return fontMap.at(fontId).getData(REGULAR)->advanceY;
 }
 
+uint8_t *GfxRenderer::getFrameBuffer() const {
+  return einkDisplay.getFrameBuffer();
+}
+
 void GfxRenderer::swapBuffers() const { einkDisplay.swapBuffers(); }
 
+void GfxRenderer::grayscaleRevert() const { einkDisplay.grayscaleRevert(); }
+
 void GfxRenderer::copyGrayscaleLsbBuffers() const { einkDisplay.copyGrayscaleLsbBuffers(einkDisplay.getFrameBuffer()); }
 
 void GfxRenderer::copyGrayscaleMsbBuffers() const { einkDisplay.copyGrayscaleMsbBuffers(einkDisplay.getFrameBuffer()); }
diff --git a/lib/GfxRenderer/GfxRenderer.h b/lib/GfxRenderer/GfxRenderer.h
index 7482cb9..d7b5925 100644
--- a/lib/GfxRenderer/GfxRenderer.h
+++ b/lib/GfxRenderer/GfxRenderer.h
@@ -46,7 +46,9 @@ class GfxRenderer {
   int getLineHeight(int fontId) const;
 
   // Low level functions
+  uint8_t* getFrameBuffer() const;
   void swapBuffers() const;
+  void grayscaleRevert() const;
   void copyGrayscaleLsbBuffers() const;
   void copyGrayscaleMsbBuffers() const;
   void displayGrayBuffer() const;
diff --git a/open-x4-sdk b/open-x4-sdk
index a126d4b..7e0dce9 160000
--- a/open-x4-sdk
+++ b/open-x4-sdk
@@ -1 +1 @@
-Subproject commit a126d4b0bf66cd2895d11748774f7ec2c366cc4c
+Subproject commit 7e0dce916706da7d80ec225fade191aea6b87fb6
diff --git a/src/screens/EpubReaderScreen.cpp b/src/screens/EpubReaderScreen.cpp
index e0a93d7..373628a 100644
--- a/src/screens/EpubReaderScreen.cpp
+++ b/src/screens/EpubReaderScreen.cpp
@@ -162,7 +162,10 @@ void EpubReaderScreen::renderScreen() {
         constexpr int y = 50;
         const int w = textWidth + margin * 2;
         const int h = renderer.getLineHeight(READER_FONT_ID) + margin * 2;
+        renderer.grayscaleRevert();
+        uint8_t *fb1 = renderer.getFrameBuffer();
         renderer.swapBuffers();
+        memcpy(fb1, renderer.getFrameBuffer(), EInkDisplay::BUFFER_SIZE);
         renderer.fillRect(x, y, w, h, 0);
         renderer.drawText(READER_FONT_ID, x + margin, y + margin, "Indexing...");
         renderer.drawRect(x + 5, y + 5, w - 10, h - 10);