Anything you do short of using real paint, the right equipment, and luck on color matching, will always look like a touch up. And it's easy to make it look worse. I believe a bicycle should be painted, used, chipped, and touched up with nail polish until it's time for a full strip and repaint. I would continue to use nail polish as you've done unless you have a paint booth, an airbrush, and proper paint. I think that bike looks fine from the photo. Has character.