You can use self-drying spray paint. There are many colors. It dries quickly, is stronger than ink, and is even. I have used it on my car, both sky blue and black. It's been over a year and it hasn't fallen off. It's basically invisible. But before spraying, sand the area to be sprayed, otherwise it won't stick. It's easy to handle! You can use nail polish to paint it and it usually won't fade. My motorcycle fuel tank is painted with red! Because there are so many colors of nail polish, you can also mix your own! When buying, make sure it’s a solid color! Don’t have any little bits and pieces of stuff in it! Hope this helps!