Update graph_generator_utils.py

graph_generator_utils.py

@@ -18,6 +18,10 @@ def add_nodes_and_edges(dot: graphviz.Digraph, parent_id: str, nodes_list: list,
     lightening_factor = 0.12 
     
     # Convert base_color hex to RGB for interpolation
+    # Ensure base_color is a valid hex string before converting
+    if not isinstance(base_color, str) or not base_color.startswith('#') or len(base_color) != 7:
+        base_color = '#19191a' # Fallback to default dark if invalid
+
     base_r = int(base_color[1:3], 16)
     base_g = int(base_color[3:5], 16)
     base_b = int(base_color[5:7], 16)