diff --git a/tests/run-tests.py b/tests/run-tests.py
--- a/tests/run-tests.py
+++ b/tests/run-tests.py
@@ -420,7 +420,7 @@
     elif options.color == 'never':
         options.color = False
     else: # 'always', for testing purposes
-        options.color = True
+        options.color = pygmentspresent
 
     global useipv6
     if options.ipv6:
@@ -1650,7 +1650,7 @@
                 else:
                     self.stream.write('\n')
                     for line in lines:
-                        if self._options.color and pygmentspresent:
+                        if self._options.color:
                             line = pygments.highlight(
                                     line,
                                     lexers.DiffLexer(),