diff --git a/.github/workflows/stale.yml b/.github/workflows/stale.yml
index d079d7a..45ed0ea 100644
--- a/.github/workflows/stale.yml
+++ b/.github/workflows/stale.yml
@@ -7,7 +7,7 @@ jobs:
   stale:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/stale@v3
+    - uses: actions/stale@v7
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
         stale-issue-message: 'This issue has been automatically marked as stale because it has not had activity in 14 days. It will be closed if no further activity occurs in 7 days'
diff --git a/octoprint_prusaslicerthumbnails/__init__.py b/octoprint_prusaslicerthumbnails/__init__.py
index 107298f..f1e51a8 100644
--- a/octoprint_prusaslicerthumbnails/__init__.py
+++ b/octoprint_prusaslicerthumbnails/__init__.py
@@ -156,8 +156,21 @@ def _extract_flashprint_thumbnail(self, gcode_encoded_images):
 		encoded_image = gcode_encoded_images[0]
 		
 		image = Image.open(io.BytesIO(encoded_image)).resize((160,120))
+		rgba = image.convert("RGBA")
+		pixels = rgba.getdata()
+		newData = []
+
+		alphamaxvalue = 35
+		for pixel in pixels:
+			if pixel[0] >= 0 and pixel[0] <= alphamaxvalue and pixel[1] >= 0 and  pixel[1] <= alphamaxvalue  and pixel[2] >= 0 and pixel[2] <= alphamaxvalue :  # finding black colour by its RGB value
+				newData.append((255, 255, 255, 0))	# storing a transparent value when we find a black/dark colour
+			else:
+				newData.append(pixel)  # other colours remain unchanged
+
+		rgba.putdata(newData)
+
 		with io.BytesIO() as png_bytes:
-			image.save(png_bytes, "PNG")
+			rgba.save(png_bytes, "PNG")
 			png_bytes_string = png_bytes.getvalue()
 		return png_bytes_string