The etiquette for wearing white to a wedding if you are not the bride can vary depending on cultural and regional norms. In many Western cultures, wearing white to a wedding as a guest is generally considered inappropriate and discouraged. White is traditionally reserved for the bride as it symbolizes purity and is meant to help her stand out on her special day. Wearing white as a guest might be seen as trying to compete with or detract attention from the bride, which can be seen as disrespectful.
As a guest, it's best to avoid wearing white or any outfit that closely resembles the color of the bride's gown. Instead, opt for other elegant and appropriate attire that adheres to the dress code specified on the wedding invitation.
Regarding bringing a guest who is not your spouse or partner, it's essential to adhere to the invitation's guidelines. Most wedding invitations will specify whether it is acceptable to bring a "plus one" or if the invitation is addressed only to the specific guest. If the invitation does not mention a "plus one," it is not appropriate to bring an additional guest. Invitations are typically extended to specific individuals, and adding an uninvited guest could place an unnecessary burden on the couple and their wedding arrangements.
If you are unsure about any aspect of the wedding etiquette, such as dress code or bringing a guest, it is perfectly acceptable to reach out to the couple or the designated contact person on the invitation to ask for clarification. Proper etiquette demonstrates thoughtfulness and respect for the couple's wishes on their special day.