Kate Middleton and Prince William started their first full day of appearances in Ottawa this morning at citizenship ceremony held outside the city's Canadian Museum of Civilization. Today, July 1, is also Canada Day. The occasion called for wearing the national colors of Canada, and Kate wore a red Maple Leaf fascinator from Lock and Co. paired with a white dress to honor their flag. The frock may look familiar – it's the same Reiss dress from Kate and Will's engagement photos! She also reportedly wore the Queen's brooch. William and Kate next hopped into an open-air carriage and headed to Parliament Hill to watch the start of a parade. The date of July 1 is also a special one for William and Kate, as it would have been Princess Diana's 50th birthday. Fans of Diana's have marked the occasion by paying tribute at her former home of Kensington Palace, where they've put cakes and flowers to commemorate the occasion.