diff --git a/conntrackt/tests/test_utils.py b/conntrackt/tests/test_utils.py
--- a/conntrackt/tests/test_utils.py
+++ b/conntrackt/tests/test_utils.py
@@ -139,6 +139,23 @@ class GetDistinctColorsTest(TestCase):
         equal = abs(colors[0].hsl["h"] + 1 - colors[12].hsl["h"] - reference) < delta
         self.assertEqual(True, equal)
 
+    def test_zero_count(self):
+        """
+        Tests if an empty list is returned in case the requested count is 0.
+        """
+
+        colors = utils.get_distinct_colors(0)
+
+        self.assertIsInstance(colors, list)
+        self.assertEqual(len(colors), 0)
+
+    def test_negative_count(self):
+        """
+        Tests if proper exception is raised in case a negative count is passed.
+        """
+
+        self.assertRaisesRegexp(ValueError, "^Count must be a non-negative integer value\.$", utils.get_distinct_colors, -10)
+
 
 class GenerateProjectDiagramTest(TestCase):
     """