Here are some things to consider:
* Personal Style: Does she typically wear bright, bold colors, or does she prefer more subtle and classic looks?
* Skin Tone: Some colors look better on certain skin tones than others.
* Outfit and Occasion: Does the nail polish complement her outfit and the event she's attending? (Fluorescent might be more appropriate for a party than a formal dinner.)
* Confidence: The most important thing is that she feels good and confident wearing the color.
Ultimately, the best color is the one she loves and makes her feel good. If she wants to rock fluorescent blue or green, she absolutely should!