added docstrings and method to create colors if empty

Author: jtsodapop

labelbox/schema/ontology.py

@@ -331,7 +331,7 @@ def _update_colors(self):
             hsv_color = (index * 1 / num_tools, 1, 1)
             rgb_color = tuple(
                 int(255 * x) for x in colorsys.hsv_to_rgb(*hsv_color))
-            if self.tools[index].color is None:
+            if self.tools[index].color == "#000000":
                 self.tools[index].color = '#%02x%02x%02x' % rgb_color
 
     @classmethod