diff --git a/server/map/__pycache__/get_markers.cpython-311.pyc b/server/map/__pycache__/get_markers.cpython-311.pyc
index 32f67260dd7d434a9a4797a16a3b99c5f9901391..73cd772e302589d49fcad61810dfeecc73eafbdd 100644
Binary files a/server/map/__pycache__/get_markers.cpython-311.pyc and b/server/map/__pycache__/get_markers.cpython-311.pyc differ
diff --git a/server/map/get_markers.py b/server/map/get_markers.py
index 7265270bb3a81f14eb3a413b53574119950ef0c7..2c8c4039928fa112a8d1feb2cb0cdd2b2b3253f2 100644
--- a/server/map/get_markers.py
+++ b/server/map/get_markers.py
@@ -84,3 +84,16 @@ def get_all_markers(self, cursor, waterBodyName):
 
     # Write marker data to response object
     self.wfile.write(marker_data.encode('utf-8'))
+
+def calculateColor(thickness: int):  # NB not final colors nor ranges
+    if 0 < thickness < 4:
+        return 0xFFff0000  # Red
+    elif 4 < thickness < 6:
+        return 0xFFff9400  # Orange
+    elif 6 < thickness < 8:
+        return 0xFFb1ff00  # Green
+    elif thickness > 8:
+        return 0xFF00d6ff  # Blue
+    else:
+        return 0xFF939393  # Gray
+