diff --git a/app.py b/app.py
index 5b8fb6c..8ada247 100644
--- a/app.py
+++ b/app.py
@@ -21,7 +21,7 @@
 
 __major_version__ = '0'
 __minor_version__ = '1'
-__change_version__ = '3'
+__change_version__ = '4'
 __version__ = '.'.join(
     (__major_version__,
      __minor_version__,
diff --git a/apps/rgb_colourspace_models_chromatically_adapted_primaries.py b/apps/rgb_colourspace_models_chromatically_adapted_primaries.py
index 8c0ff98..18d89ee 100644
--- a/apps/rgb_colourspace_models_chromatically_adapted_primaries.py
+++ b/apps/rgb_colourspace_models_chromatically_adapted_primaries.py
@@ -61,75 +61,71 @@
 APP_UID : unicode
 """
 
-LAYOUT = Div(
-    [
-        H3([Link(APP_NAME, href=APP_PATH)], className='text-center'),
-        Div([
-            Markdown(APP_DESCRIPTION),
-            H5(children='Colourspace'),
-            Dropdown(
-                id='colourspace-{0}'.format(APP_UID),
-                options=RGB_COLOURSPACES_OPTIONS,
-                value=RGB_COLOURSPACES_OPTIONS[0]['value'],
-                clearable=False),
-            H5(children='Illuminant'),
-            Dropdown(
-                id='illuminant-{0}'.format(APP_UID),
-                options=ILLUMINANTS_OPTIONS,
-                value=ILLUMINANTS_OPTIONS[0]['value'],
-                clearable=False),
-            H5(children='Chromatic Adaptation Transform'),
-            Dropdown(
-                id='chromatic-adaptation-transform-{0}'.format(APP_UID),
-                options=CHROMATIC_ADAPTATION_TRANSFORM_OPTIONS,
-                value=CHROMATIC_ADAPTATION_TRANSFORM_OPTIONS[0]['value'],
-                clearable=False),
-            H5(children='Formatter'),
-            Dropdown(
-                id='formatter-{0}'.format(APP_UID),
-                options=[{
-                    'label': 'str',
-                    'value': 'str'
-                }, {
-                    'label': 'repr',
-                    'value': 'repr'
-                }],
-                value='str',
-                clearable=False),
-            H5(children='Decimals'),
-            Slider(
-                id='decimals-{0}'.format(APP_UID),
-                min=1,
-                max=15,
-                step=1,
-                value=10,
-                marks={i + 1: str(i + 1)
-                       for i in range(15)}),
-            Pre([
-                Code(
-                    id='primaries-{0}'.format(APP_UID), className='code shell')
+LAYOUT = Div([
+    H3([Link(APP_NAME, href=APP_PATH)], className='text-center'),
+    Div([
+        Markdown(APP_DESCRIPTION),
+        H5(children='Colourspace'),
+        Dropdown(
+            id='colourspace-{0}'.format(APP_UID),
+            options=RGB_COLOURSPACES_OPTIONS,
+            value=RGB_COLOURSPACES_OPTIONS[0]['value'],
+            clearable=False),
+        H5(children='Illuminant'),
+        Dropdown(
+            id='illuminant-{0}'.format(APP_UID),
+            options=ILLUMINANTS_OPTIONS,
+            value=ILLUMINANTS_OPTIONS[0]['value'],
+            clearable=False),
+        H5(children='Chromatic Adaptation Transform'),
+        Dropdown(
+            id='chromatic-adaptation-transform-{0}'.format(APP_UID),
+            options=CHROMATIC_ADAPTATION_TRANSFORM_OPTIONS,
+            value=CHROMATIC_ADAPTATION_TRANSFORM_OPTIONS[0]['value'],
+            clearable=False),
+        H5(children='Formatter'),
+        Dropdown(
+            id='formatter-{0}'.format(APP_UID),
+            options=[{
+                'label': 'str',
+                'value': 'str'
+            }, {
+                'label': 'repr',
+                'value': 'repr'
+            }],
+            value='str',
+            clearable=False),
+        H5(children='Decimals'),
+        Slider(
+            id='decimals-{0}'.format(APP_UID),
+            min=1,
+            max=15,
+            step=1,
+            value=10,
+            marks={i + 1: str(i + 1)
+                   for i in range(15)}),
+        Pre([Code(id='primaries-{0}'.format(APP_UID), className='code shell')],
+            className='app-output'),
+        Ul([
+            Li([Link('Back to index...', href='/')],
+               className='list-inline-item'),
+            Li([
+                A('Permalink',
+                  href=urlparse.urljoin(SERVER_URL, APP_PATH),
+                  target='_blank')
             ],
-                className='app-output'),
-            Ul([
-                Li([Link('Back to index...', href='/')],
-                   className='list-inline-item'),
-                Li([
-                    A('Permalink',
-                      href=urlparse.urljoin(SERVER_URL, APP_PATH),
-                      target='_blank')
-                ],
-                   className='list-inline-item'),
-                Li([
-                    A('colour-science.org',
-                      href='http://colour-science.org',
-                      target='_blank')
-                ],
-                   className='list-inline-item'),
+               className='list-inline-item'),
+            Li([
+                A('colour-science.org',
+                  href='http://colour-science.org',
+                  target='_blank')
             ],
-               className='list-inline text-center'),
-        ])
+               className='list-inline-item'),
+        ],
+           className='list-inline text-center'),
     ],
-    className='col-6 mx-auto')
+        className='col-6 mx-auto')
+])
 """
 App layout, i.e. :class:`Div` class instance.
 
diff --git a/apps/rgb_colourspace_models_transformation_matrix.py b/apps/rgb_colourspace_models_transformation_matrix.py
index 92806cb..47b2f93 100644
--- a/apps/rgb_colourspace_models_transformation_matrix.py
+++ b/apps/rgb_colourspace_models_transformation_matrix.py
@@ -62,79 +62,78 @@
 APP_UID : unicode
 """
 
-LAYOUT = Div(
-    [
-        H3([Link(APP_NAME, href=APP_PATH)], className='text-center'),
-        Div([
-            Markdown(APP_DESCRIPTION),
-            H5(children='Input Colourspace'),
-            Dropdown(
-                id='input-colourspace-{0}'.format(APP_UID),
-                options=RGB_COLOURSPACES_OPTIONS,
-                value=RGB_COLOURSPACES_OPTIONS[0]['value'],
-                clearable=False),
-            H5(children='Output Colourspace'),
-            Dropdown(
-                id='output-colourspace-{0}'.format(APP_UID),
-                options=RGB_COLOURSPACES_OPTIONS,
-                value=RGB_COLOURSPACES_OPTIONS[0]['value'],
-                clearable=False),
-            H5(children='Chromatic Adaptation Transform'),
-            Dropdown(
-                id='chromatic-adaptation-transform-{0}'.format(APP_UID),
-                options=CHROMATIC_ADAPTATION_TRANSFORM_OPTIONS,
-                value=CHROMATIC_ADAPTATION_TRANSFORM_OPTIONS[0]['value'],
-                clearable=False),
-            H5(children='Formatter'),
-            Dropdown(
-                id='formatter-{0}'.format(APP_UID),
-                options=[{
-                    'label': 'str',
-                    'value': 'str'
-                }, {
-                    'label': 'repr',
-                    'value': 'repr'
-                }, {
-                    'label': 'Nuke',
-                    'value': 'Nuke'
-                }],
-                value='str',
-                clearable=False),
-            H5(children='Decimals'),
-            Slider(
-                id='decimals-{0}'.format(APP_UID),
-                min=1,
-                max=15,
-                step=1,
-                value=10,
-                marks={i + 1: str(i + 1)
-                       for i in range(15)}),
-            Pre([
-                Code(
-                    id='RGB-transformation-matrix-{0}'.format(APP_UID),
-                    className='code shell')
+LAYOUT = Div([
+    H3([Link(APP_NAME, href=APP_PATH)], className='text-center'),
+    Div([
+        Markdown(APP_DESCRIPTION),
+        H5(children='Input Colourspace'),
+        Dropdown(
+            id='input-colourspace-{0}'.format(APP_UID),
+            options=RGB_COLOURSPACES_OPTIONS,
+            value=RGB_COLOURSPACES_OPTIONS[0]['value'],
+            clearable=False),
+        H5(children='Output Colourspace'),
+        Dropdown(
+            id='output-colourspace-{0}'.format(APP_UID),
+            options=RGB_COLOURSPACES_OPTIONS,
+            value=RGB_COLOURSPACES_OPTIONS[0]['value'],
+            clearable=False),
+        H5(children='Chromatic Adaptation Transform'),
+        Dropdown(
+            id='chromatic-adaptation-transform-{0}'.format(APP_UID),
+            options=CHROMATIC_ADAPTATION_TRANSFORM_OPTIONS,
+            value=CHROMATIC_ADAPTATION_TRANSFORM_OPTIONS[0]['value'],
+            clearable=False),
+        H5(children='Formatter'),
+        Dropdown(
+            id='formatter-{0}'.format(APP_UID),
+            options=[{
+                'label': 'str',
+                'value': 'str'
+            }, {
+                'label': 'repr',
+                'value': 'repr'
+            }, {
+                'label': 'Nuke',
+                'value': 'Nuke'
+            }],
+            value='str',
+            clearable=False),
+        H5(children='Decimals'),
+        Slider(
+            id='decimals-{0}'.format(APP_UID),
+            min=1,
+            max=15,
+            step=1,
+            value=10,
+            marks={i + 1: str(i + 1)
+                   for i in range(15)}),
+        Pre([
+            Code(
+                id='RGB-transformation-matrix-{0}'.format(APP_UID),
+                className='code shell')
+        ],
+            className='app-output'),
+        Ul([
+            Li([Link('Back to index...', href='/')],
+               className='list-inline-item'),
+            Li([
+                A('Permalink',
+                  href=urlparse.urljoin(SERVER_URL, APP_PATH),
+                  target='_blank')
             ],
-                className='app-output'),
-            Ul([
-                Li([Link('Back to index...', href='/')],
-                   className='list-inline-item'),
-                Li([
-                    A('Permalink',
-                      href=urlparse.urljoin(SERVER_URL, APP_PATH),
-                      target='_blank')
-                ],
-                   className='list-inline-item'),
-                Li([
-                    A('colour-science.org',
-                      href='http://colour-science.org',
-                      target='_blank')
-                ],
-                   className='list-inline-item'),
+               className='list-inline-item'),
+            Li([
+                A('colour-science.org',
+                  href='http://colour-science.org',
+                  target='_blank')
             ],
-               className='list-inline text-center'),
-        ], )
+               className='list-inline-item'),
+        ],
+           className='list-inline text-center'),
     ],
-    className='col-6 mx-auto')
+        className='col-6 mx-auto')
+])
 """
 App layout, i.e. :class:`Div` class instance.