diff --git a/src/Shaders/ColorReplace.shader b/src/Shaders/ColorReplace.shader
new file mode 100644
index 000000000..99f9cb6ff
--- /dev/null
+++ b/src/Shaders/ColorReplace.shader
@@ -0,0 +1,37 @@
+shader_type canvas_item;
+render_mode unshaded;
+
+uniform vec2 size;
+
+uniform vec4 old_color;  //Our description
+uniform vec4 new_color;
+uniform float similarity_percent : hint_range(0.0, 100.0);
+
+// Must be the same size as image
+// Selected pixels are 1,1,1,1 and unselected 0,0,0,0
+uniform sampler2D selection;
+
+uniform bool has_pattern;
+uniform sampler2D pattern;
+uniform vec2 pattern_size;
+uniform vec2 pattern_uv_offset;
+
+void fragment() { // applies on each pixel seperately
+	vec4 original_color = texture(TEXTURE, UV);  // The drawing we have to use on
+	vec4 selection_color = texture(selection, UV);  // use its alpha to get portion we can ignore
+
+	vec4 col = original_color;  // Innocent till proven Guilty
+
+	float max_diff = distance(original_color, old_color);  // How much this pixel matches our description 
+	
+	float similarity = abs(2.0 - ((similarity_percent/100.0) * 2.0));
+
+	if (max_diff <= similarity)  // We found our match and pixel is proven Guilty (small is precise)
+		if (has_pattern)
+			col = textureLod(pattern, UV * (size / pattern_size) + pattern_uv_offset, 0.0);
+		else
+			col = new_color;
+
+	// Mix selects original color if there is selection or col if there is none
+	COLOR = mix(original_color, col, selection_color.a);
+}
diff --git a/src/Tools/Bucket.gd b/src/Tools/Bucket.gd
index b270b6b43..abf294106 100644
--- a/src/Tools/Bucket.gd
+++ b/src/Tools/Bucket.gd
@@ -1,7 +1,10 @@
 extends BaseTool
 
+const ColorReplaceShader := preload("res://src/Shaders/ColorReplace.shader")
+
 var _prev_mode := 0
 var _pattern: Patterns.Pattern
+var _similarity := 100
 var _fill_area := 0
 var _fill_with := 0
 var _offset_x := 0
@@ -20,9 +23,11 @@ func _input(event: InputEvent) -> void:
 	if event.is_action("ctrl"):
 		options.selected = _prev_mode ^ 1
 		_fill_area = options.selected
+		$Similarity.visible = (_fill_area == 1)
 	if event.is_action_released("ctrl"):
 		options.selected = _prev_mode
 		_fill_area = options.selected
+		$Similarity.visible = (_fill_area == 1)
 
 
 func _on_FillAreaOptions_item_selected(index: int) -> void:
@@ -33,6 +38,20 @@ func _on_FillAreaOptions_item_selected(index: int) -> void:
 
 func _on_FillWithOptions_item_selected(index: int) -> void:
 	_fill_with = index
+	$Similarity/Value.value = _similarity
+	update_config()
+	save_config()
+
+
+func _on_Value_value_changed(value: float) -> void:
+	_similarity = value
+	$Similarity/Slider.value = _similarity
+	update_config()
+	save_config()
+
+
+func _on_Slider_value_changed(value: float) -> void:
+	_similarity = value
 	update_config()
 	save_config()
 
@@ -64,11 +83,12 @@ func _on_PatternOffsetY_value_changed(value: float) -> void:
 
 func get_config() -> Dictionary:
 	if !_pattern:
-		return {}
+		return {"fill_area": _fill_area, "fill_with": _fill_with, "similarity": _similarity}
 	return {
 		"pattern_index": _pattern.index,
 		"fill_area": _fill_area,
 		"fill_with": _fill_with,
+		"similarity": _similarity,
 		"offset_x": _offset_x,
 		"offset_y": _offset_y,
 	}
@@ -80,6 +100,7 @@ func set_config(config: Dictionary) -> void:
 		_pattern = Global.patterns_popup.get_pattern(index)
 	_fill_area = config.get("fill_area", _fill_area)
 	_fill_with = config.get("fill_with", _fill_with)
+	_similarity = config.get("similarity", _similarity)
 	_offset_x = config.get("offset_x", _offset_x)
 	_offset_y = config.get("offset_y", _offset_y)
 	update_pattern()
@@ -88,6 +109,9 @@ func set_config(config: Dictionary) -> void:
 func update_config() -> void:
 	$FillAreaOptions.selected = _fill_area
 	$FillWithOptions.selected = _fill_with
+	$Similarity.visible = (_fill_area == 1)
+	$Similarity/Value.value = _similarity
+	$Similarity/Slider.value = _similarity
 	$Mirror.visible = _fill_area == 0
 	$FillPattern.visible = _fill_with == 1
 	$FillPattern/XOffset/OffsetX.value = _offset_x
@@ -151,13 +175,37 @@ func fill_in_color(position: Vector2) -> void:
 			if tool_slot.color.is_equal_approx(color):
 				return
 
-		for x in Global.current_project.size.x:
-			for y in Global.current_project.size.y:
-				var pos := Vector2(x, y)
-				if project.has_selection and not project.can_pixel_get_drawn(pos):
-					continue
-				if image.get_pixelv(pos).is_equal_approx(color):
-					_set_pixel(image, x, y, tool_slot.color)
+		var selection: Image
+		var selection_tex := ImageTexture.new()
+		if project.has_selection:
+			selection = project.bitmap_to_image(project.selection_bitmap, false)
+		else:
+			selection = Image.new()
+			selection.create(project.size.x, project.size.y, false, Image.FORMAT_RGBA8)
+			selection.fill(Color(1, 1, 1, 1))
+
+		selection_tex.create_from_image(selection)
+
+		var pattern_tex := ImageTexture.new()
+		if _pattern:
+			pattern_tex.create_from_image(_pattern.image)
+
+		var params := {
+			"size": project.size,
+			"old_color": color,
+			"new_color": tool_slot.color,
+			"similarity_percent": _similarity,
+			"selection": selection_tex,
+			"pattern": pattern_tex,
+			"pattern_size": pattern_tex.get_size(),
+			# pixel offset converted to pattern uv offset
+			"pattern_uv_offset":
+			Vector2.ONE / pattern_tex.get_size() * Vector2(_offset_x, _offset_y),
+			"has_pattern": true if _fill_with == 1 else false
+		}
+		var gen := ShaderImageEffect.new()
+		gen.generate_image(image, ColorReplaceShader, params, project.size)
+		yield(gen, "done")
 
 
 func fill_in_area(position: Vector2) -> void:
diff --git a/src/Tools/Bucket.tscn b/src/Tools/Bucket.tscn
index c3adb6a70..19eacccea 100644
--- a/src/Tools/Bucket.tscn
+++ b/src/Tools/Bucket.tscn
@@ -22,6 +22,8 @@ corner_radius_bottom_left = 5
 anti_aliasing = false
 
 [node name="ToolOptions" instance=ExtResource( 2 )]
+margin_right = 138.0
+margin_bottom = 105.0
 script = ExtResource( 3 )
 
 [node name="Label" parent="." index="0"]
@@ -43,10 +45,58 @@ margin_bottom = 56.0
 mouse_default_cursor_shape = 2
 size_flags_horizontal = 4
 text = "Same color area"
-items = [ "Same color area", null, false, 0, null, "Same color pixels", null, false, 1, null ]
+items = [ "Same color area", null, false, 0, null, "Similar color pixels", null, false, 1, null ]
 selected = 0
 
-[node name="FillWith" type="Label" parent="." index="3"]
+[node name="Similarity" type="VBoxContainer" parent="." index="3"]
+visible = false
+margin_top = 60.0
+margin_right = 131.0
+margin_bottom = 122.0
+alignment = 1
+
+[node name="Label" type="Label" parent="Similarity" index="0"]
+margin_left = 33.0
+margin_right = 97.0
+margin_bottom = 14.0
+size_flags_horizontal = 4
+text = "Similarity:"
+
+[node name="Value" type="SpinBox" parent="Similarity" index="1"]
+margin_left = 28.0
+margin_top = 18.0
+margin_right = 102.0
+margin_bottom = 42.0
+hint_tooltip = "How much two colors are Similar/Close together"
+mouse_default_cursor_shape = 2
+size_flags_horizontal = 4
+step = 0.001
+value = 100.0
+align = 1
+suffix = "%"
+__meta__ = {
+"_editor_description_": ""
+}
+
+[node name="Slider" type="HSlider" parent="Similarity" index="2"]
+margin_left = 19.0
+margin_top = 46.0
+margin_right = 111.0
+margin_bottom = 62.0
+rect_min_size = Vector2( 92, 0 )
+hint_tooltip = "How much two colors are Similar/Close together"
+focus_mode = 0
+mouse_default_cursor_shape = 2
+size_flags_horizontal = 4
+size_flags_vertical = 1
+step = 0.001
+value = 100.0
+ticks_on_borders = true
+__meta__ = {
+"_editor_description_": ""
+}
+
+[node name="FillWith" type="Label" parent="." index="4"]
 margin_left = 38.0
 margin_top = 60.0
 margin_right = 92.0
@@ -54,7 +104,7 @@ margin_bottom = 74.0
 size_flags_horizontal = 4
 text = "Fill with:"
 
-[node name="FillWithOptions" type="OptionButton" parent="." index="4"]
+[node name="FillWithOptions" type="OptionButton" parent="." index="5"]
 margin_left = 5.0
 margin_top = 78.0
 margin_right = 126.0
@@ -65,7 +115,7 @@ text = "Selected Color"
 items = [ "Selected Color", null, false, 0, null, "Pattern", null, false, 1, null ]
 selected = 0
 
-[node name="FillPattern" type="VBoxContainer" parent="." index="5"]
+[node name="FillPattern" type="VBoxContainer" parent="." index="6"]
 visible = false
 margin_left = 22.0
 margin_top = 102.0
@@ -137,16 +187,16 @@ margin_right = 85.0
 margin_bottom = 24.0
 mouse_default_cursor_shape = 2
 
-[node name="PixelPerfect" parent="." index="6"]
+[node name="PixelPerfect" parent="." index="7"]
 visible = false
 
-[node name="EmptySpacer" parent="." index="7"]
+[node name="EmptySpacer" parent="." index="8"]
 visible = false
 margin_top = 212.0
 margin_right = 131.0
 margin_bottom = 224.0
 
-[node name="Mirror" parent="." index="8"]
+[node name="Mirror" parent="." index="9"]
 visible = false
 margin_top = 212.0
 margin_right = 131.0
@@ -161,6 +211,8 @@ margin_left = 86.0
 margin_right = 103.0
 
 [connection signal="item_selected" from="FillAreaOptions" to="." method="_on_FillAreaOptions_item_selected"]
+[connection signal="value_changed" from="Similarity/Value" to="." method="_on_Value_value_changed"]
+[connection signal="value_changed" from="Similarity/Slider" to="." method="_on_Slider_value_changed"]
 [connection signal="item_selected" from="FillWithOptions" to="." method="_on_FillWithOptions_item_selected"]
 [connection signal="pressed" from="FillPattern/Type" to="." method="_on_PatternType_pressed"]
 [connection signal="value_changed" from="FillPattern/XOffset/OffsetX" to="." method="_on_PatternOffsetX_value_changed"]