Recent years have seen the royals donning similar attire and colours when the world is watching them at big events - with Camilla, Anne and Sarah Ferguson all donning green on Easter Sunday.
Kate crouched down to chat to seven-year-old Oscar Burrow, from Lancaster, who raised more than £40,000 for Derian House Children s Hospice in Chorley, Lancashire.
For the third year in a row, Kate, Princess of Wales, will return to Westminster Abbey on December 8 to film the festive special for broadcast on Christmas Eve