diff --git a/setup.py b/setup.py
index a321aa1..2160077 100644
--- a/setup.py
+++ b/setup.py
@@ -35,7 +35,8 @@ extras_require = {
         'psycopg2>=2.5.1',
         'pytz>=2014.2',
         'python-dateutil>=2.2',
-        'pymysql'
+        'pymysql',
+        'colour>=0.0.4'
     ],
     'anyjson': ['anyjson>=0.3.3'],
     'babel': ['Babel>=1.3'],
diff --git a/sqlalchemy_utils/types/color.py b/sqlalchemy_utils/types/color.py
index 0064243..dbe743f 100644
--- a/sqlalchemy_utils/types/color.py
+++ b/sqlalchemy_utils/types/color.py
@@ -6,8 +6,9 @@ from .scalar_coercible import ScalarCoercible
 colour = None
 try:
     import colour
+    python_colour_type = colour.Color
 except ImportError:
-    pass
+    python_colour_type = None
 
 
 class ColorType(types.TypeDecorator, ScalarCoercible):
@@ -49,7 +50,7 @@ class ColorType(types.TypeDecorator, ScalarCoercible):
     """
     STORE_FORMAT = u'hex'
     impl = types.Unicode(20)
-    python_type = colour.Color
+    python_type = python_colour_type
 
     def __init__(self, max_length=20, *args, **kwargs):
         # Fail if colour is not found.
diff --git a/tests/types/test_color.py b/tests/types/test_color.py
index 5d970b1..5af476b 100644
--- a/tests/types/test_color.py
+++ b/tests/types/test_color.py
@@ -6,7 +6,7 @@ from sqlalchemy_utils.types import color
 from tests import TestCase
 
 
-@mark.skipif('color.colour is None')
+@mark.skipif('color.python_colour_type is None')
 class TestColorType(TestCase):
     def create_models(self):
         class Document(self.Base):