[El Sol Infinito]

The paint pen trick works great for the speedo numbers, just make sure its primed correctly and use a light touch. I didn't end up having to repaint the black parts, thankfully, because it sure seems that masking off those narrow numbers would really suck. If I had to do it, however, I would look into using a product called airbrush friskit or else some type of liquid mask.
Good luck.