diff --git a/data/widgets/tools_configuration.xml b/data/widgets/tools_configuration.xml
index 41927e4ad..33a9b9a05 100644
--- a/data/widgets/tools_configuration.xml
+++ b/data/widgets/tools_configuration.xml
@@ -31,9 +31,12 @@
             <label text="Angle:" />
             <slider min="0" max="180" name="brush_angle" cell_align="horizontal" />
 
-            <label text="Opacity:" />
+            <label text="Opacity:" name="opacity_label" />
 	    <slider min="0" max="255" name="opacity" cell_align="horizontal" />
 
+            <label text="Tolerance:" name="tolerance_label" />
+	    <slider min="0" max="255" name="tolerance" cell_align="horizontal" />
+
 	  </grid>
 	  <box name="brush_preview_box" /><!-- custom widget -->
         </box>
diff --git a/src/commands/cmd_configure_tools.cpp b/src/commands/cmd_configure_tools.cpp
index 0e3e8b7f2..1051e777f 100644
--- a/src/commands/cmd_configure_tools.cpp
+++ b/src/commands/cmd_configure_tools.cpp
@@ -51,6 +51,7 @@ static bool brush_size_slider_change_hook(JWidget widget, void *data);
 static bool brush_angle_slider_change_hook(JWidget widget, void *data);
 static bool brush_type_change_hook(JWidget widget, void *data);
 static bool opacity_slider_change_hook(JWidget widget, void *data);
+static bool tolerance_slider_change_hook(JWidget widget, void *data);
 static bool spray_width_slider_change_hook(JWidget widget, void *data);
 static bool air_speed_slider_change_hook(JWidget widget, void *data);
 static bool tiled_check_change_hook(JWidget widget, void *data);
@@ -94,6 +95,7 @@ static void on_current_tool_change()
   Widget* brush_type = window->findChild("brush_type");
   Widget* brush_preview = window->findChild("brush_preview");
   Widget* opacity = window->findChild("opacity");
+  Widget* tolerance = window->findChild("tolerance");
   Widget* spray_width = window->findChild("spray_width");
   Widget* air_speed = window->findChild("air_speed");
 
@@ -106,6 +108,7 @@ static void on_current_tool_change()
     ->getToolSettings(current_tool);
 
   jslider_set_value(opacity, tool_settings->getOpacity());
+  jslider_set_value(tolerance, tool_settings->getTolerance());
   jslider_set_value(brush_size, tool_settings->getPen()->getSize());
   jslider_set_value(brush_angle, tool_settings->getPen()->getAngle());
   jslider_set_value(spray_width, tool_settings->getSprayWidth());
@@ -139,7 +142,7 @@ ConfigureTools::ConfigureTools()
 void ConfigureTools::onExecute(Context* context)
 {
   JWidget tiled, tiled_x, tiled_y, snap_to_grid, view_grid, pixel_grid, set_grid;
-  JWidget brush_size, brush_angle, opacity;
+  JWidget brush_size, brush_angle, opacity, tolerance;
   JWidget spray_width, air_speed;
   JWidget brush_preview_box;
   JWidget brush_type_box, brush_type;
@@ -169,6 +172,7 @@ void ConfigureTools::onExecute(Context* context)
 		"brush_size", &brush_size,
 		"brush_angle", &brush_angle,
 		"opacity", &opacity,
+		"tolerance", &tolerance,
 		"spray_width", &spray_width,
 		"air_speed", &air_speed,
 		"brush_preview_box", &brush_preview_box,
@@ -244,6 +248,7 @@ void ConfigureTools::onExecute(Context* context)
     HOOK(brush_angle, JI_SIGNAL_SLIDER_CHANGE, brush_angle_slider_change_hook, brush_preview);
     HOOK(brush_type, SIGNAL_GROUP_BUTTON_CHANGE, brush_type_change_hook, brush_preview);
     HOOK(opacity, JI_SIGNAL_SLIDER_CHANGE, opacity_slider_change_hook, 0);
+    HOOK(tolerance, JI_SIGNAL_SLIDER_CHANGE, tolerance_slider_change_hook, 0);
     HOOK(air_speed, JI_SIGNAL_SLIDER_CHANGE, air_speed_slider_change_hook, 0);
     HOOK(spray_width, JI_SIGNAL_SLIDER_CHANGE, spray_width_slider_change_hook, 0);
     HOOK(check_onionskin, JI_SIGNAL_CHECK_CHANGE, onionskin_check_change_hook, 0);
@@ -382,6 +387,14 @@ static bool opacity_slider_change_hook(JWidget widget, void *data)
   return false;
 }
 
+static bool tolerance_slider_change_hook(JWidget widget, void *data)
+{
+  ISettings* settings = UIContext::instance()->getSettings();
+  Tool* current_tool = settings->getCurrentTool();
+  settings->getToolSettings(current_tool)->setTolerance(jslider_get_value(widget));
+  return false;
+}
+
 static bool spray_width_slider_change_hook(JWidget widget, void *data)
 {
   ISettings* settings = UIContext::instance()->getSettings();
diff --git a/src/raster/algo.h b/src/raster/algo.h
index bba333978..0ff96c00e 100644
--- a/src/raster/algo.h
+++ b/src/raster/algo.h
@@ -42,7 +42,7 @@ double algo_spline_get_tan(double x0, double y0, double x1, double y1,
 			   double x2, double y2, double x3, double y3,
 			   double in_x);
 
-void algo_floodfill(Image* image, int x, int y, void* data, AlgoHLine proc);
+void algo_floodfill(Image* image, int x, int y, int tolerance, void* data, AlgoHLine proc);
 
 void algo_polygon(int vertices, const int* points, void* data, AlgoHLine proc);
 
diff --git a/src/raster/algofill.cpp b/src/raster/algofill.cpp
index 999efb6ca..6b056cce1 100644
--- a/src/raster/algofill.cpp
+++ b/src/raster/algofill.cpp
@@ -48,19 +48,54 @@ static int flood_count;          /* number of flooded segments */
 
 #define FLOOD_LINE(c)            (((FLOODED_LINE *)_scratch_mem) + c)
 
-static inline bool color_equal_32(ase_uint32 c1, ase_uint32 c2)
+static inline bool color_equal_32(ase_uint32 c1, ase_uint32 c2, int tolerance)
 {
-  return (c1 == c2) || (_rgba_geta(c1) == 0 && _rgba_geta(c2) == 0);
+  if (tolerance == 0)
+    return (c1 == c2) || (_rgba_geta(c1) == 0 && _rgba_geta(c2) == 0);
+  else {
+    int r1 = _rgba_getr(c1);
+    int g1 = _rgba_getg(c1);
+    int b1 = _rgba_getb(c1);
+    int a1 = _rgba_geta(c1);
+    int r2 = _rgba_getr(c2);
+    int g2 = _rgba_getg(c2);
+    int b2 = _rgba_getb(c2);
+    int a2 = _rgba_geta(c2);
+
+    if (a1 == 0 && a2 == 0)
+      return true;
+
+    return ((ABS(r1-r2) <= tolerance) &&
+	    (ABS(g1-g2) <= tolerance) &&
+	    (ABS(b1-b2) <= tolerance) &&
+	    (ABS(a1-a2) <= tolerance));
+  }
 }
 
-static inline bool color_equal_16(ase_uint16 c1, ase_uint16 c2)
+static inline bool color_equal_16(ase_uint16 c1, ase_uint16 c2, int tolerance)
 {
-  return (c1 == c2) || (_graya_geta(c1) == 0 && _graya_geta(c2) == 0);
+  if (tolerance == 0)
+    return (c1 == c2) || (_graya_geta(c1) == 0 && _graya_geta(c2) == 0);
+  else {
+    int k1 = _graya_getv(c1);
+    int a1 = _graya_geta(c1);
+    int k2 = _graya_getv(c2);
+    int a2 = _graya_geta(c2);
+
+    if (a1 == 0 && a2 == 0)
+      return true;
+
+    return ((ABS(k1-k2) <= tolerance) &&
+	    (ABS(a1-a2) <= tolerance));
+  }
 }
 
-static inline bool color_equal_8(ase_uint8 c1, ase_uint8 c2)
+static inline bool color_equal_8(ase_uint8 c1, ase_uint8 c2, int tolerance)
 {
-  return (c1 == c2);
+  if (tolerance == 0)
+    return (c1 == c2);
+  else
+    return ABS(c1-c2) <= tolerance;
 }
 
 
@@ -71,7 +106,7 @@ static inline bool color_equal_8(ase_uint8 c1, ase_uint8 c2)
  *  the part of the line which it has dealt with.
  */
 static int flooder (Image *image, int x, int y,
-		    int src_color, void *data, AlgoHLine proc)
+		    int src_color, int tolerance, void *data, AlgoHLine proc)
 {
   FLOODED_LINE *p;
   int left = 0, right = 0;
@@ -84,18 +119,18 @@ static int flooder (Image *image, int x, int y,
         ase_uint32 *address = ((ase_uint32 **)image->line)[y];
 
         /* check start pixel */
-        if (!color_equal_32((int)*(address+x), src_color))
+        if (!color_equal_32((int)*(address+x), src_color, tolerance))
           return x+1;
 
         /* work left from starting point */
         for (left=x-1; left>=0; left--) {
-          if (!color_equal_32((int)*(address+left), src_color))
+          if (!color_equal_32((int)*(address+left), src_color, tolerance))
             break;
         }
 
         /* work right from starting point */
         for (right=x+1; right<image->w; right++) {
-          if (!color_equal_32((int)*(address+right), src_color))
+          if (!color_equal_32((int)*(address+right), src_color, tolerance))
             break;
         }
       }
@@ -106,18 +141,18 @@ static int flooder (Image *image, int x, int y,
         ase_uint16 *address = ((ase_uint16 **)image->line)[y];
 
         /* check start pixel */
-        if (!color_equal_16((int)*(address+x), src_color))
+        if (!color_equal_16((int)*(address+x), src_color, tolerance))
           return x+1;
 
         /* work left from starting point */
         for (left=x-1; left>=0; left--) {
-          if (!color_equal_16((int)*(address+left), src_color))
+          if (!color_equal_16((int)*(address+left), src_color, tolerance))
             break;
         }
 
         /* work right from starting point */
         for (right=x+1; right<image->w; right++) {
-          if (!color_equal_16((int)*(address+right), src_color))
+          if (!color_equal_16((int)*(address+right), src_color, tolerance))
             break;
         }
       }
@@ -128,18 +163,18 @@ static int flooder (Image *image, int x, int y,
         ase_uint8 *address = ((ase_uint8 **)image->line)[y];
 
         /* check start pixel */
-        if (!color_equal_8((int)*(address+x), src_color))
+        if (!color_equal_8((int)*(address+x), src_color, tolerance))
           return x+1;
 
         /* work left from starting point */
         for (left=x-1; left>=0; left--) {
-          if (!color_equal_8((int)*(address+left), src_color))
+          if (!color_equal_8((int)*(address+left), src_color, tolerance))
             break;
         }
 
         /* work right from starting point */
         for (right=x+1; right<image->w; right++) {
-          if (!color_equal_8((int)*(address+right), src_color))
+          if (!color_equal_8((int)*(address+right), src_color, tolerance))
             break;
         }
       }
@@ -207,8 +242,8 @@ static int flooder (Image *image, int x, int y,
  *  segments which have already been drawn in order to minimise the required
  *  number of tests.
  */
-static int check_flood_line(Image *image, int y, int left, int right,
-			    int src_color, void *data, AlgoHLine proc)
+static int check_flood_line(Image* image, int y, int left, int right,
+			    int src_color, int tolerance, void *data, AlgoHLine proc)
 {
   int c;
   FLOODED_LINE *p;
@@ -228,7 +263,7 @@ static int check_flood_line(Image *image, int y, int left, int right,
       c = p->next;
 
       if (!c) {
-        left = flooder (image, left, y, src_color, data, proc);
+        left = flooder (image, left, y, src_color, tolerance, data, proc);
         ret = true;
         break;
       }
@@ -243,7 +278,7 @@ static int check_flood_line(Image *image, int y, int left, int right,
 /* floodfill:
  *  Fills an enclosed area (starting at point x, y) with the specified color.
  */
-void algo_floodfill(Image *image, int x, int y, void *data, AlgoHLine proc)
+void algo_floodfill(Image* image, int x, int y, int tolerance, void *data, AlgoHLine proc)
 {
   int src_color;
   int c, done;
@@ -270,7 +305,7 @@ void algo_floodfill(Image *image, int x, int y, void *data, AlgoHLine proc)
   }
 
   /* start up the flood algorithm */
-  flooder(image, x, y, src_color, data, proc);
+  flooder(image, x, y, src_color, tolerance, data, proc);
 
   /* continue as long as there are some segments still to test */
   do {
@@ -285,7 +320,7 @@ void algo_floodfill(Image *image, int x, int y, void *data, AlgoHLine proc)
       if (p->flags & FLOOD_TODO_BELOW) {
         p->flags &= ~FLOOD_TODO_BELOW;
         if (check_flood_line(image, p->y+1, p->lpos, p->rpos,
-			     src_color, data, proc)) {
+			     src_color, tolerance, data, proc)) {
           done = false;
           p = FLOOD_LINE(c);
         }
@@ -295,7 +330,7 @@ void algo_floodfill(Image *image, int x, int y, void *data, AlgoHLine proc)
       if (p->flags & FLOOD_TODO_ABOVE) {
         p->flags &= ~FLOOD_TODO_ABOVE;
         if (check_flood_line(image, p->y-1, p->lpos, p->rpos,
-			     src_color, data, proc)) {
+			     src_color, tolerance, data, proc)) {
           done = false;
           /* special case shortcut for going backwards */
           if ((c < image->h) && (c > 0))
diff --git a/src/raster/pen.cpp b/src/raster/pen.cpp
index 17dfbe108..169e812bc 100644
--- a/src/raster/pen.cpp
+++ b/src/raster/pen.cpp
@@ -135,7 +135,7 @@ void Pen::regenerate_pen()
       image_line(m_image, r+x3, r+y3, r+x4, r+y4, 1);
       image_line(m_image, r+x4, r+y4, r+x1, r+y1, 1);
 
-      algo_floodfill(m_image, r, r, m_image, algo_hline);
+      algo_floodfill(m_image, r, r, 0, m_image, algo_hline);
       break;
     }
 
diff --git a/src/settings/settings.h b/src/settings/settings.h
index f85993f43..b54f891f2 100644
--- a/src/settings/settings.h
+++ b/src/settings/settings.h
@@ -97,12 +97,14 @@ public:
   virtual IPenSettings* getPen() = 0;
 
   virtual int getOpacity() = 0;
+  virtual int getTolerance() = 0;
   virtual bool getFilled() = 0;
   virtual bool getPreviewFilled() = 0;
   virtual int getSprayWidth() = 0;
   virtual int getSpraySpeed() = 0;
 
   virtual void setOpacity(int opacity) = 0;
+  virtual void setTolerance(int tolerance) = 0;
   virtual void setFilled(bool state) = 0;
   virtual void setSprayWidth(int width) = 0;
   virtual void setSpraySpeed(int speed) = 0;
diff --git a/src/settings/ui_settings_impl.cpp b/src/settings/ui_settings_impl.cpp
index 0dff04980..a640e4f69 100644
--- a/src/settings/ui_settings_impl.cpp
+++ b/src/settings/ui_settings_impl.cpp
@@ -311,6 +311,7 @@ class UIToolSettingsImpl : public IToolSettings
   Tool* m_tool;
   UIPenSettingsImpl m_pen;
   int m_opacity;
+  int m_tolerance;
   bool m_filled;
   bool m_previewFilled;
   int m_spray_width;
@@ -325,6 +326,8 @@ public:
 
     m_opacity = get_config_int(cfg_section.c_str(), "Opacity", 255);
     m_opacity = MID(0, m_opacity, 255);
+    m_tolerance = get_config_int(cfg_section.c_str(), "Tolerance", 0);
+    m_tolerance = MID(0, m_tolerance, 255);
     m_filled = false;
     m_previewFilled = get_config_bool(cfg_section.c_str(), "PreviewFilled", false);
     m_spray_width = 16;
@@ -348,6 +351,7 @@ public:
     std::string cfg_section(getCfgSection());
 
     set_config_int(cfg_section.c_str(), "Opacity", m_opacity);
+    set_config_int(cfg_section.c_str(), "Tolerance", m_tolerance);
     set_config_int(cfg_section.c_str(), "PenType", m_pen.getType());
     set_config_int(cfg_section.c_str(), "PenSize", m_pen.getSize());
     set_config_int(cfg_section.c_str(), "PenAngle", m_pen.getAngle());
@@ -364,12 +368,14 @@ public:
   IPenSettings* getPen() { return &m_pen; }
 
   int getOpacity() { return m_opacity; }
+  int getTolerance() { return m_tolerance; }
   bool getFilled() { return m_filled; }
   bool getPreviewFilled() { return m_previewFilled; }
   int getSprayWidth() { return m_spray_width; }
   int getSpraySpeed() { return m_spray_speed; }
 
   void setOpacity(int opacity) { m_opacity = opacity; }
+  void setTolerance(int tolerance) { m_tolerance = tolerance; }
   void setFilled(bool state) { m_filled = state; }
   void setPreviewFilled(bool state) { m_previewFilled = state; }
   void setSprayWidth(int width) { m_spray_width = width; }
diff --git a/src/tools/point_shapes.h b/src/tools/point_shapes.h
index e8a2fac83..0a00c91a5 100644
--- a/src/tools/point_shapes.h
+++ b/src/tools/point_shapes.h
@@ -74,7 +74,7 @@ class FloodFillPointShape : public ToolPointShape
 public:
   void transformPoint(IToolLoop* loop, int x, int y)
   {
-    algo_floodfill(loop->getSrcImage(), x, y, loop, (AlgoHLine)doInkHline);
+    algo_floodfill(loop->getSrcImage(), x, y, loop->getTolerance(), loop, (AlgoHLine)doInkHline);
   }
   void getModifiedArea(IToolLoop* loop, int x, int y, Rect& area)
   {
diff --git a/src/tools/tool.h b/src/tools/tool.h
index 8972e146a..348e2966e 100644
--- a/src/tools/tool.h
+++ b/src/tools/tool.h
@@ -276,6 +276,9 @@ public:
   // Returns the opacity to be used by the ink (ToolInk).
   virtual int getOpacity() = 0;
 
+  // Returns the tolerance to be used by the ink (ToolInk).
+  virtual int getTolerance() = 0;
+
   // Returns true if each scanline generated by a ToolPointShape must
   // be "tiled".  See the method ToolPointShape::doInkHline to check
   // how this member is used. When tiled mode is activated, each
diff --git a/src/widgets/editor/editor.cpp b/src/widgets/editor/editor.cpp
index d7efaa694..30edfae12 100644
--- a/src/widgets/editor/editor.cpp
+++ b/src/widgets/editor/editor.cpp
@@ -1784,6 +1784,7 @@ class ToolLoopImpl : public IToolLoop
   Mask* m_mask;
   Point m_maskOrigin;
   int m_opacity;
+  int m_tolerance;
   Point m_offset;
   Point m_speed;
   bool m_canceled;
@@ -1888,6 +1889,7 @@ public:
 					  Point(0, 0));
 
     m_opacity = settings->getToolSettings(m_tool)->getOpacity();
+    m_tolerance = settings->getToolSettings(m_tool)->getTolerance();
     m_speed.x = 0;
     m_speed.y = 0;
 
@@ -2032,6 +2034,7 @@ public:
   int getSecondaryColor() { return m_secondary_color; }
   void setSecondaryColor(int color) { m_secondary_color = color; }
   int getOpacity() { return m_opacity; }
+  int getTolerance() { return m_tolerance; }
   TiledMode getTiledMode() { return m_tiled_mode; }
   bool getFilled() { return m_filled; }
   bool getPreviewFilled() { return m_previewFilled; }