Used the Django's versioning utilities.

colorful/__init__.py

@@ -1 +1,9 @@
-VERSION = (1, 1, 0)
+from __future__ import unicode_literals
+
+from django.utils import version
+
+__all__ = ['VERSION', '__version__']
+
+VERSION = (1, 2, 0, 'alpha', 0)
+
+__version__ = version.get_version(VERSION)

setup.py

@@ -1,11 +1,11 @@
 #!/usr/bin/env python
-from setuptools import setup, find_packages
+from setuptools import find_packages, setup
 
-from colorful import VERSION
+import colorful
 
 setup(
     name='django-colorful',
-    version='.'.join(str(v) for v in VERSION),
+    version=colorful.__version__,
     description='An extension to the Django web framework that provides database and form color fields',
     long_description=open('README.rst').read(),
     url='https://github.com/charettes/django-colorful',

tox.ini

@@ -32,10 +32,12 @@ commands =
     flake8
 deps =
     flake8
+    Django<1.10
 
 [testenv:isort]
 basepython = python2.7
 commands =
     isort --recursive --check-only --diff colorful tests
 deps =
     isort==4.1.0
+    Django<1.10