Replaced random color generator

c4ctrl.py

@@ -604,14 +604,27 @@ class ColorScheme:
         return topic.lower().rfind("/master") == len(topic)-7 # 7 = len("/master")
 
     def _random_color(self):
-        """Returns a random 6 char hex color."""
-        from random import randint
+        """Returns a 3*4 bit pseudo random color in 6 char hex notation."""
+        from random import randint, sample
+        chls = [15]
+        chls.append(randint(0,15))
+        chls.append(randint(0,7) - chls[1])
+        if chls[2] < 0: chls[2] = 0
+
         color = ""
-        for i in range(6):
-            # Dont return smaller values than 11
-            color = color + hex(randint(1, 15))[2:]
+        for ch in sample(chls, k=3):
+            color += hex(ch)[2:]*2
         return color
 
+    #def _random_color(self):
+    #    """Returns a random 6 char hex color."""
+    #    from random import randint
+    #    color = ""
+    #    for i in range(6):
+    #        # Dont return smaller values than 11
+    #        color = color + hex(randint(1, 15))[2:]
+    #    return color
+
     def color_for(self, topic):
         """Returns the color (hex) this ColorScheme provides for the given topic."""
         if self.mapping: