diff --git a/src/Shaders/AutoInvertColors.shader b/src/Shaders/AutoInvertColors.shader
new file mode 100644
index 000000000..7296e9d6d
--- /dev/null
+++ b/src/Shaders/AutoInvertColors.shader
@@ -0,0 +1,25 @@
+shader_type canvas_item;
+
+
+vec3 rgb2hsb(vec3 c){
+	vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
+	vec4 p = mix(vec4(c.bg, K.wz),
+				vec4(c.gb, K.xy),
+				step(c.b, c.g));
+	vec4 q = mix(vec4(p.xyw, c.r),
+				vec4(c.r, p.yzx),
+				step(p.x, c.r));
+	float d = q.x - min(q.w, q.y);
+	float e = 1.0e-10;
+	return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)),
+				d / (q.x + e),
+				q.x);
+}
+
+
+void fragment() {
+	vec3 screen_color = rgb2hsb(textureLod(SCREEN_TEXTURE, SCREEN_UV, 0.0).rgb);
+	if(screen_color.z < 0.5){
+		COLOR.rgb = vec3(1.0) - COLOR.rgb;
+	}
+}
diff --git a/src/Tools/LineTool.gd b/src/Tools/LineTool.gd
index c6dc00ca2..3c2c1fbd5 100644
--- a/src/Tools/LineTool.gd
+++ b/src/Tools/LineTool.gd
@@ -112,7 +112,7 @@ func draw_preview() -> void:
 		canvas.draw_set_transform(start - t_offsetv, canvas.rotation, canvas.scale)
 
 		for line in _create_polylines(indicator):
-			canvas.draw_polyline(PoolVector2Array(line), tool_slot.color)
+			canvas.draw_polyline(PoolVector2Array(line), Color.black)
 
 		canvas.draw_set_transform(canvas.position, canvas.rotation, canvas.scale)
 
diff --git a/src/Tools/ShapeDrawer.gd b/src/Tools/ShapeDrawer.gd
index e83b9683e..fb5640ce9 100644
--- a/src/Tools/ShapeDrawer.gd
+++ b/src/Tools/ShapeDrawer.gd
@@ -105,7 +105,7 @@ func draw_preview() -> void:
 		canvas.draw_set_transform(rect.position - t_offsetv, canvas.rotation, canvas.scale)
 
 		for line in _create_polylines(indicator):
-			canvas.draw_polyline(PoolVector2Array(line), tool_slot.color)
+			canvas.draw_polyline(PoolVector2Array(line), Color.black)
 
 		canvas.draw_set_transform(canvas.position, canvas.rotation, canvas.scale)
 
diff --git a/src/UI/Canvas/Canvas.tscn b/src/UI/Canvas/Canvas.tscn
index c23c9d8c2..d7302dc96 100644
--- a/src/UI/Canvas/Canvas.tscn
+++ b/src/UI/Canvas/Canvas.tscn
@@ -1,4 +1,4 @@
-[gd_scene load_steps=12 format=2]
+[gd_scene load_steps=14 format=2]
 
 [ext_resource path="res://src/UI/Canvas/Canvas.gd" type="Script" id=1]
 [ext_resource path="res://src/UI/Canvas/Grid.gd" type="Script" id=2]
@@ -9,6 +9,7 @@
 [ext_resource path="res://src/UI/Canvas/Previews.gd" type="Script" id=7]
 [ext_resource path="res://src/UI/Canvas/Selection.gd" type="Script" id=8]
 [ext_resource path="res://src/Shaders/MarchingAntsOutline.shader" type="Shader" id=9]
+[ext_resource path="res://src/Shaders/AutoInvertColors.shader" type="Shader" id=10]
 
 [sub_resource type="CanvasItemMaterial" id=1]
 blend_mode = 4
@@ -22,6 +23,9 @@ shader_param/width = 0.05
 shader_param/frequency = 200.0
 shader_param/stripe_direction = 0.5
 
+[sub_resource type="ShaderMaterial" id=4]
+shader = ExtResource( 10 )
+
 [node name="Canvas" type="Node2D"]
 script = ExtResource( 1 )
 
@@ -58,4 +62,5 @@ centered = false
 script = ExtResource( 3 )
 
 [node name="Previews" type="Node2D" parent="."]
+material = SubResource( 4 )
 script = ExtResource( 7 )