If there is a note attached to a wedding invitation requesting that guests wear all white, the proper response would be to respect the dress code and wear an all-white outfit as requested. The couple has likely chosen this dress code for a specific reason, and honoring their wishes is a way to show respect and support for their wedding vision.
If you have any questions or concerns about the dress code or need clarification, it's appropriate to reach out to the couple directly or the designated point of contact provided in the invitation. They will appreciate your consideration and communication.
Remember that weddings are special occasions, and dressing according to the couple's wishes helps create a harmonious atmosphere and adds to the overall celebration.