use tango pygments theme

docs/conf.py

@@ -75,7 +75,7 @@ intersphinx_mapping = {
 }
 
 # The name of the Pygments (syntax highlighting) style to use.
-pygments_style = 'trac'
+pygments_style = 'tango'
 
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,