Test: Fixed test to contain expected colors

- Problem was that Linux has been upgrading 16-color output, and the test was
  based on observed output, which looks correct, but actually isn't.
  We may end up marking these tests as expeected to fail, because they are not
  important.

test/color.rules.t

@@ -232,19 +232,15 @@ class TestColorRulesMerging(TestCase):
 
     def test_colors_merge(self):
         """Tests whether colors merge"""
-        code, out, err = self.t('hometask')
-
-        self.assertIn('\x1b[38;5;160', out)  # Red foreground applied
-        self.assertIn('\x1b[48;5;7', out)    # White background applied
+        code, out, err = self.t('1 info')
+        self.assertIn('\x1b[31;47mhometask', out)  # Red on white
 
     def test_colors_merge_off(self):
         """No color merge behaviour with rule.color.merge=no"""
         self.t.config('rule.color.merge', 'no')
 
-        code, out, err = self.t('hometask')
-
-        self.assertIn('\x1b[38;5;160', out)  # Red foreground applied
-        self.assertNotIn('\x1b[48;5;7', out) # White background not applied
+        code, out, err = self.t('1 info')
+        self.assertIn('\x1b[31mhometask', out)  # Red
 
 
 if __name__ == "__main__":