Actually...Not at all. Neon colors may contrast well with a darker skin tone, but not specifically pleasing to the eye, certain seasons, certain tan skin tones, and any old outfit. Really, it's not only about skin. Rather than going ahead and diving into neon that wont match your outfit or skin tone you should go for something more subtle. I think pastel colors are more suitable to the eye, no? And, you can wear dark colors, just contrast it with another nail polish color.
Honestly, dark and vivid colors are very likable so don't pass out on them. Rather, when you wear a black, don't do a solid color, use white or silver too.
When using gold you must contrast it as well. It doesn't give a radiant vibe for a lot of people. It's not right for people. Rather than just gold why not toss in silver or black. Make a nice design out of it.
I think that blue and red are great colors for tan skin. Green and pink as well. Light, subtle, smoothing colors go a long way with tan skin. Again, just design. Instead of having plain blue, use a white or silver glitter nail polish at the top to make it look like falling snow or a night sky.
Yellow is something you should embrace as well. Instead of having a bright, closer to neon colored nail polish, try a lighter color. Something that's gentle and fragile.
When using dark colors don't use to much. Contrast it with a nice vibrant color.
As a girl of the tan, always getting tanner, I know how to contrast by now. Use all the colors you want. Just keep in mind, make it match.
1. Make it match your outfit, not only your skin tone.
2. Make it match your personality.
3. Make it pleasurable to the eye. Not blinding.
4. Contrast the darker colors with a brighter color.
5. Design your nails. Simple or extravagant.
6. Match the season and time of day or special event.
7. Don't limit yourself with colors because you're not a lighter skin tone. Take all the colors you want and splash it on that nail.
8. Use blue and red. It's not dull or "drab". You just have to make it appear better by using what you have. Don't bore yourself with plain colors. People tend to wear the same shade of nail polish because they think that it matches best with their nail, but they get tired of it. Red and blue are looked down upon because so many tan girl use it. But, they used that same shade with no style or appearance. Just design.
If you're wondering how you design your nail and make it look nice without the hassle or paying a lot of money...all you need is a bobby pin, nail polish, and a toothpick. Make your own designs.
Have fun.