Is it appropriate for a woman in her early thirties who is already working to wear bright lipstick?

Women in their thirties can wear bright lipstick as long as they like, regardless of whether they work or not, and there is nothing wrong with that.

If you don't see the old ladies dancing in the square, many of them in their fifties, aren't also wearing bright lipstick? No one shames them.

Lipstick is not for yourself, but for others. If you wear overly bright lipstick at work, there's no problem as long as it doesn't lead to any other suspicions from your coworkers.