diff --git a/rb2bl_colors.py b/rb2bl_colors.py
new file mode 100644
index 0000000..622f173
--- /dev/null
+++ b/rb2bl_colors.py
@@ -0,0 +1,59 @@
+import os
+import sys
+import json
+from pprint import pprint
+from typing import Optional, List
+from pathlib import Path
+
+def read_color_data(color_id: str) -> Optional[str]:
+    """
+    Read BrickLink color ID from a JSON file for a given color ID.
+
+    Args:
+        color_id: The color ID to look up
+
+    Returns:
+        The BrickLink ID if found, None otherwise
+    """
+    try:
+        with open(f"colors/{color_id}.json", 'r') as file:
+            data = json.load(file)
+            bricklink_data = data['external_ids'].get('BrickLink', {})
+            return bricklink_data.get('ext_ids', [None])[0] if bricklink_data else None
+    except (FileNotFoundError, KeyError, json.JSONDecodeError):
+        return None
+
+def process_colors_file(input_file: str, output_file: str) -> None:
+    """
+    Process the colors.csv file and create a new combined file with BrickLink IDs.
+
+    Args:
+        input_file: Path to the input colors.csv file
+        output_file: Path to write the output file
+    """
+    new_file: List[str] = []
+
+    try:
+        with open(input_file) as file:
+            lines = file.readlines()
+
+        # Process header
+        new_file.append('id,name,rgb,is_trans,BrickLink\n')
+
+        # Process data lines
+        for line in lines[1:]:
+            id, name, rgb, is_trans = line.strip().split(',')
+            bricklink_id = read_color_data(id)
+            new_file.append(f"{id},{name},{rgb},{is_trans},{bricklink_id}\n")
+
+        # Write output file
+        with open(output_file, "w") as f:
+            f.writelines(new_file)
+
+    except Exception as e:
+        print(f"Error processing file: {e}")
+
+if __name__ == "__main__":
+    input_file = "colors.csv"
+    output_file = "colors_combined.csv"
+    process_colors_file(input_file, output_file)