diff --git a/papers/commands/init_cmd.py b/papers/commands/init_cmd.py
index 1d1b717..a2e9dc6 100644
--- a/papers/commands/init_cmd.py
+++ b/papers/commands/init_cmd.py
@@ -12,8 +12,8 @@ def parser(subparsers, config):
     parser.add_argument('-p', '--path', default=None,
                         help='path to papers directory (if none, ~/.papers is used)')
     parser.add_argument('-d', '--doc-dir', default=None,
-                        help=('path to document directory '
-                        '(if none, documents are stored in the same directory)'))
+                        help=('path to document directory (if none, documents '
+                              'are stored in the same directory)'))
     return parser
 
 
@@ -33,4 +33,4 @@ def command(config, ui, path, doc_dir):
     else:
         ui.error('papers already present in {}.'.format(
                  ui.colored(papersdir, 'filepath')))
-        exit(-1)
+        ui.exit()
diff --git a/papers/commands/open_cmd.py b/papers/commands/open_cmd.py
index 221933d..559fd88 100644
--- a/papers/commands/open_cmd.py
+++ b/papers/commands/open_cmd.py
@@ -1,6 +1,5 @@
 import subprocess
 
-from ..color import colored
 from .. import repo
 from ..paper import NoDocumentFile
 from .. import configs
@@ -19,9 +18,10 @@ def command(config, ui, citekey):
     paper = rp.paper_from_ref(citekey, fatal=True)
     try:
         filepath = paper.get_document_path()
-        subprocess.Popen([config.get(configs.MAIN_SECTION, 'open-cmd'), filepath])
-        print("%s opened." % colored(filepath, 'filepath'))
+        subprocess.Popen([config.get(configs.MAIN_SECTION, 'open-cmd'),
+                          filepath])
+        print("%s opened." % ui.colored(filepath, 'filepath'))
     except NoDocumentFile:
-        print("%s: No document associated to this entry %s."
-                % (colored('error', 'error'), colored(citekey, 'citekey')))
-        exit(-1)
+        ui.error("No document associated with the entry %s."
+                 % ui.colored(citekey, 'citekey'))
+        ui.exit()