diff --git a/data/pref.xml b/data/pref.xml
index 704683a2b..29b19df7e 100644
--- a/data/pref.xml
+++ b/data/pref.xml
@@ -237,6 +237,7 @@
     <section id="quantization">
       <option id="with_alpha" type="bool" default="true" />
       <option id="dithering_algorithm" type="std::string" />
+      <option id="dithering_factor" type="int" default="100" />
     </section>
     <section id="eyedropper" text="Editor">
       <option id="channel" type="EyedropperChannel" default="EyedropperChannel::COLOR_ALPHA" />
diff --git a/data/strings/en.ini b/data/strings/en.ini
index 49395e7af..ec8820c47 100644
--- a/data/strings/en.ini
+++ b/data/strings/en.ini
@@ -482,6 +482,7 @@ delete = &Delete
 
 [color_mode]
 title = Color Mode
+amount = Amount:
 flatten = Merge layers
 
 [convolution_matrix]
diff --git a/data/widgets/color_mode.xml b/data/widgets/color_mode.xml
index b0e0fb84b..d2a7c26ac 100644
--- a/data/widgets/color_mode.xml
+++ b/data/widgets/color_mode.xml
@@ -1,5 +1,6 @@
 <!-- Aseprite -->
-<!-- Copyright (C) 2017 by David Capello -->
+<!-- Copyright (C) 2019  Igara Studio S.A. -->
+<!-- Copyright (C) 2017  David Capello -->
 <gui>
 <window id="color_mode" text="@.title">
   <vbox>
@@ -8,6 +9,11 @@
     </view>
     <slider min="0" max="100" id="progress" minwidth="100" />
     <hbox id="dithering_placeholder" />
+    <hbox id="amount">
+      <label text="@.amount" />
+      <slider min="0" max="100" id="factor" minwidth="100" />
+      <label text="%" />
+    </hbox>
     <check text="@.flatten" id="flatten" />
     <separator horizontal="true" />
     <hbox>
diff --git a/src/app/cmd/set_pixel_format.cpp b/src/app/cmd/set_pixel_format.cpp
index d7e9b4298..db9a9c610 100644
--- a/src/app/cmd/set_pixel_format.cpp
+++ b/src/app/cmd/set_pixel_format.cpp
@@ -1,4 +1,5 @@
 // Aseprite
+// Copyright (C) 2019  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
@@ -69,6 +70,7 @@ SetPixelFormat::SetPixelFormat(Sprite* sprite,
                                const PixelFormat newFormat,
                                const render::DitheringAlgorithm ditheringAlgorithm,
                                const render::DitheringMatrix& ditheringMatrix,
+                               const double ditheringFactor,
                                render::TaskDelegate* delegate)
   : WithSprite(sprite)
   , m_oldFormat(sprite->pixelFormat())
@@ -86,6 +88,7 @@ SetPixelFormat::SetPixelFormat(Sprite* sprite,
       (old_image.get(), nullptr, newFormat,
        ditheringAlgorithm,
        ditheringMatrix,
+       ditheringFactor,
        sprite->rgbMap(cel->frame()),
        sprite->palette(cel->frame()),
        cel->layer()->isBackground(),
diff --git a/src/app/cmd/set_pixel_format.h b/src/app/cmd/set_pixel_format.h
index d033baebf..40ec6a919 100644
--- a/src/app/cmd/set_pixel_format.h
+++ b/src/app/cmd/set_pixel_format.h
@@ -1,4 +1,5 @@
 // Aseprite
+// Copyright (C) 2019  Igara Studio S.A.
 // Copyright (C) 2001-2017  David Capello
 //
 // This program is distributed under the terms of
@@ -32,6 +33,7 @@ namespace cmd {
                    const doc::PixelFormat newFormat,
                    const render::DitheringAlgorithm ditheringAlgorithm,
                    const render::DitheringMatrix& ditheringMatrix,
+                   const double ditheringFactor,
                    render::TaskDelegate* delegate);
 
   protected:
diff --git a/src/app/commands/cmd_change_pixel_format.cpp b/src/app/commands/cmd_change_pixel_format.cpp
index b3db46213..ab9453d3f 100644
--- a/src/app/commands/cmd_change_pixel_format.cpp
+++ b/src/app/commands/cmd_change_pixel_format.cpp
@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2019 Igara Studio S.A.
+// Copyright (C) 2019  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
@@ -79,6 +79,7 @@ public:
                 const doc::PixelFormat pixelFormat,
                 const render::DitheringAlgorithm ditheringAlgorithm,
                 const render::DitheringMatrix& ditheringMatrix,
+                const double ditheringFactor,
                 const gfx::Point& pos,
                 const bool newBlend)
     : m_image(dstImage)
@@ -92,11 +93,13 @@ public:
        pixelFormat,
        ditheringAlgorithm,
        ditheringMatrix,
+       ditheringFactor,
        newBlend]() { // Copy the matrix
         run(sprite, frame,
             pixelFormat,
             ditheringAlgorithm,
             ditheringMatrix,
+            ditheringFactor,
             newBlend);
       })
   {
@@ -121,6 +124,7 @@ private:
            const doc::PixelFormat pixelFormat,
            const render::DitheringAlgorithm ditheringAlgorithm,
            const render::DitheringMatrix& ditheringMatrix,
+           const double ditheringFactor,
            const bool newBlend) {
     doc::ImageRef tmp(
       Image::create(sprite->pixelFormat(),
@@ -142,6 +146,7 @@ private:
       pixelFormat,
       ditheringAlgorithm,
       ditheringMatrix,
+      ditheringFactor,
       sprite->rgbMap(frame),
       sprite->palette(frame),
       (sprite->backgroundLayer() != nullptr),
@@ -208,6 +213,11 @@ public:
       m_ditheringSelector->Change.connect(
         base::Bind<void>(&ColorModeWindow::onDithering, this));
       ditheringPlaceholder()->addChild(m_ditheringSelector);
+
+      factor()->Change.connect(base::Bind<void>(&ColorModeWindow::onDithering, this));
+    }
+    else {
+      amount()->setVisible(false);
     }
     if (from != IMAGE_GRAYSCALE)
       colorMode()->addChild(new ConversionItem(IMAGE_GRAYSCALE));
@@ -221,6 +231,9 @@ public:
 
     progress()->setReadOnly(true);
 
+    // Default dithering factor
+    factor()->setValue(Preferences::instance().quantization.ditheringFactor());
+
     // Select first option
     colorMode()->selectIndex(0);
   }
@@ -244,6 +257,10 @@ public:
                                   render::BayerMatrix(8));
   }
 
+  double ditheringFactor() const {
+    return double(factor()->getValue()) / 100.0;
+  }
+
   bool flattenEnabled() const {
     return flatten()->isSelected();
   }
@@ -252,7 +269,14 @@ public:
   void saveDitheringAlgorithm() {
     if (m_ditheringSelector) {
       if (auto item = m_ditheringSelector->getSelectedItem()) {
-        Preferences::instance().quantization.ditheringAlgorithm(item->text());
+        Preferences::instance().quantization.ditheringAlgorithm(
+          item->text());
+
+        if (m_ditheringSelector->ditheringAlgorithm() ==
+            render::DitheringAlgorithm::ErrorDiffusion) {
+          Preferences::instance().quantization.ditheringFactor(
+            factor()->getValue());
+        }
       }
     }
   }
@@ -285,8 +309,15 @@ private:
 
     doc::PixelFormat dstPixelFormat = item->pixelFormat();
 
-    if (m_ditheringSelector)
-      m_ditheringSelector->setVisible(dstPixelFormat == doc::IMAGE_INDEXED);
+    if (m_ditheringSelector) {
+      const bool toIndexed = (dstPixelFormat == doc::IMAGE_INDEXED);
+      m_ditheringSelector->setVisible(toIndexed);
+
+      const bool errorDiff =
+        (m_ditheringSelector->ditheringAlgorithm() ==
+         render::DitheringAlgorithm::ErrorDiffusion);
+      amount()->setVisible(toIndexed && errorDiff);
+    }
 
     m_image.reset(
       Image::create(dstPixelFormat,
@@ -315,6 +346,7 @@ private:
         dstPixelFormat,
         ditheringAlgorithm(),
         ditheringMatrix(),
+        ditheringFactor(),
         visibleBounds.origin(),
         Preferences::instance().experimental.newBlend()));
 
@@ -373,6 +405,7 @@ private:
   doc::PixelFormat m_format;
   render::DitheringAlgorithm m_ditheringAlgorithm;
   render::DitheringMatrix m_ditheringMatrix;
+  double m_ditheringFactor;
 };
 
 ChangePixelFormatCommand::ChangePixelFormatCommand()
@@ -381,6 +414,7 @@ ChangePixelFormatCommand::ChangePixelFormatCommand()
   m_useUI = true;
   m_format = IMAGE_RGB;
   m_ditheringAlgorithm = render::DitheringAlgorithm::None;
+  m_ditheringFactor = 1.0;
 }
 
 void ChangePixelFormatCommand::onLoadParams(const Params& params)
@@ -483,6 +517,7 @@ void ChangePixelFormatCommand::onExecute(Context* context)
     m_format = window.pixelFormat();
     m_ditheringAlgorithm = window.ditheringAlgorithm();
     m_ditheringMatrix = window.ditheringMatrix();
+    m_ditheringFactor = window.ditheringFactor();
     flatten = window.flattenEnabled();
 
     window.saveDitheringAlgorithm();
@@ -520,6 +555,7 @@ void ChangePixelFormatCommand::onExecute(Context* context)
             sprite, m_format,
             m_ditheringAlgorithm,
             m_ditheringMatrix,
+            m_ditheringFactor,
             &job));             // SpriteJob is a render::TaskDelegate
       });
     job.waitJob();
diff --git a/src/app/commands/cmd_new_layer.cpp b/src/app/commands/cmd_new_layer.cpp
index 148a28a6a..e5bd55527 100644
--- a/src/app/commands/cmd_new_layer.cpp
+++ b/src/app/commands/cmd_new_layer.cpp
@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2019 Igara Studio S.A.
+// Copyright (C) 2019  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
@@ -283,7 +283,7 @@ void NewLayerCommand::onExecute(Context* context)
               nullptr,
               sprite->pixelFormat(),
               render::DitheringAlgorithm::None,
-              render::DitheringMatrix(),
+              render::DitheringMatrix(), 1.0,
               sprite->rgbMap(dstFrame),
               pasteSpr->palette(fr),
               (pasteSpr->backgroundLayer() ? true: false),
diff --git a/src/app/commands/cmd_paste_text.cpp b/src/app/commands/cmd_paste_text.cpp
index 55b85e11a..95d44a469 100644
--- a/src/app/commands/cmd_paste_text.cpp
+++ b/src/app/commands/cmd_paste_text.cpp
@@ -1,4 +1,5 @@
 // Aseprite
+// Copyright (C) 2019  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
@@ -184,7 +185,7 @@ void PasteTextCommand::onExecute(Context* ctx)
           render::convert_pixel_format(
             image.get(), NULL, sprite->pixelFormat(),
             render::DitheringAlgorithm::None,
-            render::DitheringMatrix(),
+            render::DitheringMatrix(), 1.0,
             rgbmap, sprite->palette(editor->frame()),
             false, 0));
       }
diff --git a/src/app/doc_exporter.cpp b/src/app/doc_exporter.cpp
index fd4de3cfc..22fd6a2c7 100644
--- a/src/app/doc_exporter.cpp
+++ b/src/app/doc_exporter.cpp
@@ -744,7 +744,7 @@ void DocExporter::renderTexture(Context* ctx, const Samples& samples, Image* tex
         sample.sprite(),
         textureImage->pixelFormat(),
         render::DitheringAlgorithm::None,
-        render::DitheringMatrix(),
+        render::DitheringMatrix(), 1.0,
         nullptr)                // TODO add a delegate to show progress
         .execute(ctx);
     }
diff --git a/src/app/file/gif_format.cpp b/src/app/file/gif_format.cpp
index e57faf4f0..1e361e64e 100644
--- a/src/app/file/gif_format.cpp
+++ b/src/app/file/gif_format.cpp
@@ -746,7 +746,7 @@ private:
         render::convert_pixel_format
         (oldImage, NULL, IMAGE_RGB,
          render::DitheringAlgorithm::None,
-         render::DitheringMatrix(),
+         render::DitheringMatrix(), 1.0,
          nullptr,
          m_sprite->palette(cel->frame()),
          m_opaque,
@@ -759,7 +759,7 @@ private:
       render::convert_pixel_format
       (m_currentImage.get(), NULL, IMAGE_RGB,
        render::DitheringAlgorithm::None,
-       render::DitheringMatrix(),
+       render::DitheringMatrix(), 1.0,
        nullptr,
        m_sprite->palette(m_frameNum),
        m_opaque,
@@ -769,7 +769,7 @@ private:
       render::convert_pixel_format
       (m_previousImage.get(), NULL, IMAGE_RGB,
        render::DitheringAlgorithm::None,
-       render::DitheringMatrix(),
+       render::DitheringMatrix(), 1.0,
        nullptr,
        m_sprite->palette(MAX(0, m_frameNum-1)),
        m_opaque,
diff --git a/src/app/ui/dithering_selector.cpp b/src/app/ui/dithering_selector.cpp
index fead5ca7d..fadaeac92 100644
--- a/src/app/ui/dithering_selector.cpp
+++ b/src/app/ui/dithering_selector.cpp
@@ -1,4 +1,5 @@
 // Aseprite
+// Copyright (C) 2019  Igara Studio S.A.
 // Copyright (C) 2017  David Capello
 //
 // This program is distributed under the terms of
@@ -101,7 +102,8 @@ private:
       doc::clear_image(image2.get(), 0);
       render::convert_pixel_format(
         image1.get(), image2.get(), IMAGE_INDEXED,
-        m_algo, m_matrix, nullptr, palette, true, -1, nullptr);
+        m_algo, m_matrix, 1.0,
+        nullptr, palette, true, -1, nullptr);
     }
 
     m_preview = os::instance()->createRgbaSurface(w, h);
diff --git a/src/app/util/clipboard.cpp b/src/app/util/clipboard.cpp
index 66818cf37..6adf06718 100644
--- a/src/app/util/clipboard.cpp
+++ b/src/app/util/clipboard.cpp
@@ -367,7 +367,7 @@ void paste()
           render::convert_pixel_format(
             clipboard_image.get(), NULL, dstSpr->pixelFormat(),
             render::DitheringAlgorithm::None,
-            render::DitheringMatrix(),
+            render::DitheringMatrix(), 1.0,
             dst_rgbmap, clipboard_palette.get(),
             false,
             0));
diff --git a/src/app/util/create_cel_copy.cpp b/src/app/util/create_cel_copy.cpp
index ceab5c07d..e80b3f071 100644
--- a/src/app/util/create_cel_copy.cpp
+++ b/src/app/util/create_cel_copy.cpp
@@ -1,4 +1,5 @@
 // Aseprite
+// Copyright (C) 2019  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
@@ -54,7 +55,7 @@ Cel* create_cel_copy(const Cel* srcCel,
       tmpImage.get(),
       IMAGE_RGB,
       render::DitheringAlgorithm::None,
-      render::DitheringMatrix(),
+      render::DitheringMatrix(), 1.0,
       srcCel->sprite()->rgbMap(srcCel->frame()),
       srcCel->sprite()->palette(srcCel->frame()),
       srcCel->layer()->isBackground(),
@@ -65,7 +66,7 @@ Cel* create_cel_copy(const Cel* srcCel,
       dstCel->image(),
       IMAGE_INDEXED,
       render::DitheringAlgorithm::None,
-      render::DitheringMatrix(),
+      render::DitheringMatrix(), 1.0,
       dstSprite->rgbMap(dstFrame),
       dstSprite->palette(dstFrame),
       srcCel->layer()->isBackground(),
diff --git a/src/render/error_diffusion.cpp b/src/render/error_diffusion.cpp
index 48213eccf..b066dbd97 100644
--- a/src/render/error_diffusion.cpp
+++ b/src/render/error_diffusion.cpp
@@ -25,13 +25,15 @@ ErrorDiffusionDither::ErrorDiffusionDither(int transparentIndex)
 
 void ErrorDiffusionDither::start(
   const doc::Image* srcImage,
-  doc::Image* dstImage)
+  doc::Image* dstImage,
+  const double factor)
 {
   m_srcImage = srcImage;
   m_width = 2+srcImage->width();
   for (int i=0; i<kChannels; ++i)
     m_err[i].resize(m_width*2, 0);
   m_lastY = -1;
+  m_factor = int(factor * 100.0);
 }
 
 void ErrorDiffusionDither::finish()
@@ -89,11 +91,11 @@ doc::color_t ErrorDiffusionDither::ditherRgbToIndex2D(
   // TODO using Floyd-Steinberg matrix here but it should be configurable
   for (int i=0; i<kChannels; ++i) {
     int* err = &m_err[i][x];
-
-    const int a = quantError[i] * 7 / 16;
-    const int b = quantError[i] * 3 / 16;
-    const int c = quantError[i] * 5 / 16;
-    const int d = quantError[i] * 1 / 16;
+    const int q = quantError[i] * m_factor / 100;
+    const int a = q * 7 / 16;
+    const int b = q * 3 / 16;
+    const int c = q * 5 / 16;
+    const int d = q * 1 / 16;
 
     if (y & 1) {
       err[0        ] += a;
diff --git a/src/render/error_diffusion.h b/src/render/error_diffusion.h
index a545fe156..e9344c5db 100644
--- a/src/render/error_diffusion.h
+++ b/src/render/error_diffusion.h
@@ -23,7 +23,8 @@ namespace render {
     bool zigZag() const override { return true; }
     void start(
       const doc::Image* srcImage,
-      doc::Image* dstImage) override;
+      doc::Image* dstImage,
+      const double factor) override;
     void finish() override;
     doc::color_t ditherRgbToIndex2D(
       const int x, const int y,
@@ -35,6 +36,7 @@ namespace render {
     int m_width, m_lastY;
     static const int kChannels = 4;
     std::vector<int> m_err[kChannels];
+    int m_factor;
   };
 
 } // namespace render
diff --git a/src/render/ordered_dither.cpp b/src/render/ordered_dither.cpp
index 12440658f..8176f8fff 100644
--- a/src/render/ordered_dither.cpp
+++ b/src/render/ordered_dither.cpp
@@ -229,6 +229,7 @@ doc::color_t OrderedDither2::ditherRgbPixelToIndex(
 void dither_rgb_image_to_indexed(
   DitheringAlgorithmBase& algorithm,
   const DitheringMatrix& matrix,
+  const double factor,
   const doc::Image* srcImage,
   doc::Image* dstImage,
   const doc::RgbMap* rgbmap,
@@ -238,7 +239,7 @@ void dither_rgb_image_to_indexed(
   const int w = srcImage->width();
   const int h = srcImage->height();
 
-  algorithm.start(srcImage, dstImage);
+  algorithm.start(srcImage, dstImage, factor);
 
   if (algorithm.dimensions() == 1) {
     const doc::LockImageBits<doc::RgbTraits> srcBits(srcImage);
diff --git a/src/render/ordered_dither.h b/src/render/ordered_dither.h
index 18a8a2dc1..64651f6b8 100644
--- a/src/render/ordered_dither.h
+++ b/src/render/ordered_dither.h
@@ -29,7 +29,8 @@ namespace render {
 
     virtual void start(
       const doc::Image* srcImage,
-      doc::Image* dstImage) { }
+      doc::Image* dstImage,
+      const double factor) { }
 
     virtual void finish() { }
 
@@ -77,6 +78,7 @@ namespace render {
   void dither_rgb_image_to_indexed(
     DitheringAlgorithmBase& algorithm,
     const DitheringMatrix& matrix,
+    const double factor,
     const doc::Image* srcImage,
     doc::Image* dstImage,
     const doc::RgbMap* rgbmap,
diff --git a/src/render/quantization.cpp b/src/render/quantization.cpp
index d75b591a5..0dba27640 100644
--- a/src/render/quantization.cpp
+++ b/src/render/quantization.cpp
@@ -86,6 +86,7 @@ Image* convert_pixel_format(
   PixelFormat pixelFormat,
   DitheringAlgorithm ditheringAlgorithm,
   const DitheringMatrix& ditheringMatrix,
+  const double ditheringFactor,
   const RgbMap* rgbmap,
   const Palette* palette,
   bool is_background,
@@ -114,7 +115,8 @@ Image* convert_pixel_format(
     }
     if (dither)
       dither_rgb_image_to_indexed(
-        *dither, ditheringMatrix, image, new_image, rgbmap, palette, delegate);
+        *dither, ditheringMatrix, ditheringFactor,
+        image, new_image, rgbmap, palette, delegate);
     return new_image;
   }
 
diff --git a/src/render/quantization.h b/src/render/quantization.h
index a76d64eee..01e7640b1 100644
--- a/src/render/quantization.h
+++ b/src/render/quantization.h
@@ -55,6 +55,7 @@ namespace render {
     doc::PixelFormat pixelFormat,
     render::DitheringAlgorithm ditheringAlgorithm,
     const render::DitheringMatrix& ditheringMatrix,
+    const double ditheringFactor,
     const doc::RgbMap* rgbmap,
     const doc::Palette* palette,
     bool is_background,