diff --git a/src/example3.py b/src/example3.py
index 43080ca..e86f513 100644
--- a/src/example3.py
+++ b/src/example3.py
@@ -8,9 +8,9 @@ Harness.add(Node('X2', num_pins=10, ports_left=True))
 Harness.add(Cable('W1', num_wires=10, color_code='IEC'))
 Harness.objects['W1'].connect_all_straight('X1','X2')
 
-Harness.add(Node('X3', num_pins=10, ports_right=True))
-Harness.add(Node('X4', num_pins=10, ports_left=True))
-Harness.add(Cable('W2', num_wires=10, color_code='DIN'))
+Harness.add(Node('X3', num_pins=20, ports_right=True))
+Harness.add(Node('X4', num_pins=20, ports_left=True))
+Harness.add(Cable('W2', num_wires=20, color_code='DIN'))
 Harness.objects['W2'].connect_all_straight('X3','X4')
 
 Harness.graphviz()
diff --git a/src/wireviz.py b/src/wireviz.py
index 496f489..8027296 100644
--- a/src/wireviz.py
+++ b/src/wireviz.py
@@ -1,6 +1,7 @@
 
-COLOR_CODE_DIN = ['WH','BN','GN','YE','GY','PK','BU','RD','BK','VT']
-COLOR_CODE_IEC = ['BN','RD','OG','YE','GN','BU','VT','GY','WH','BK']
+COLOR_CODES = {'DIN': ['WH','BN','GN','YE','GY','PK','BU','RD','BK','VT'],
+               'IEC': ['BN','RD','OG','YE','GN','BU','VT','GY','WH','BK'],
+               'BW':  ['BK','WH']}
 
 color_hex = {
              'BK': '#000000',
@@ -174,12 +175,8 @@ class Cable:
                 if num_wires is None:
                     raise Exception('Unknown number of wires')
                 else:
-                    # TODO: Loop through colors if num_wires > len(COLOR_CODE_XXX)
-                    if color_code == 'DIN':
-                        self.colors = tuple(COLOR_CODE_DIN[:num_wires])
-                    elif color_code == 'IEC':
-                        self.colors = tuple(COLOR_CODE_IEC[:num_wires])
-                    else:
+                    # choose color code
+                    if color_code not in COLOR_CODES:
                         raise Exception('Unknown color code')
             else:
                 if num_wires is None: