The Princess of Wales said she believed the late Queen was looking down on them when five rainbows appeared in the sky over Balmoral.
Kate made the comment as she and William thanked people who had worked to stage Queen Elizabeth’s funeral in Windsor.
It came as the Royals remarked at seeing the colourful weather phenomenon as they spent time in Scotland.
The Prince of Wales said the unusual sight had left them surprised, adding ‘In Scotland, how many rainbows turned up?’
‘You hardly ever see rainbows up there, but there were five.’
Kate smiled as she replied: ‘Her Majesty was looking down on us.’
The Union flag is lowered on Windsor Castle as a rainbow covers the sky on day of the Queen’s death
Kate, Princess of Wales, and Prince William attended Windsor Guildhall this afternoon, three days after the funeral of Her late Majesty the Queen, to speak with staff and volunteers who helped organise and run the committal service at St George’s Chapel in Winsdor on Monday
The Princess of Wales remained elegant and composed as she met with staff and volunteers and spoke to them about how they managed to organise a seamless, poignant ceremony to say farewell to Her late Majesty
It came as the Royal couple told volunteers and operational staff who helped to organise the Queen’s Committal Service that moments of sadness still caught him out.
They had arrived at Windsor Guildhall today to pass on their appreciation to volunteers and staff who worked on the service at St George’s Chapel – which followed Her Majesty’s state funeral at Westminster Abbey.
And during the engagement, which was the first in person engagement for the Prince and Princess of Wales since the state funeral, William said he found himself ‘choked up’ when he saw Paddington Bear tributes to his grandmother, but had found comfort in the public outpouring of support for the Royal Family.
He said: ‘It is the things you don’t expect that get to you,’ he said, adding that he got ‘choked up’ over the Paddington tributes. He went on: ‘It is always very comforting that so many people care. It makes it a lot better.
‘There are certain moments that catch you out. You are prepared for all but certain moments catch you out.’
They also thanked the group for supporting the large crowds that gathered in Windsor to commemorate the Queen and watch the procession of her coffin up the Long Walk to the castle before the service.
The Prince and Princess of Wales met with staff, who were also dressed in black to pay their respects to Her late Majesty during the period of mourning
The Prince and Princess of Wales (pictured) have met with volunteers and operational staff to thank them for their work on the Queen ‘s committal service at Windsor Castle
William and Kate arrived at Windsor Guildhall on Thursday for their first royal engagement since the late monarch’s funeral
The Royal Family were not expected to carry out any official engagements during their mourning period, after more than a week of being under the world’s gaze while performing ceremonial duties following the Queen’s death.
But yesterday William made his first speech since his grandmother passed away with a pre-recorded address to the Earthshot Prize summit.
Buckingham Palace say a small number of engagements will be undertaken during royal mourning to thank those involved in the delivery of HM Queen Elizabeth’s Funeral.
Princess Anne, 72, has also stepped out at Portsmouth Naval Base, where she shook hands with Royal Navy personnel who took part in the procession.
It was her first engagement since attending her mother’s funeral on Monday.
Speaking to staff, the prince asked whether the Queen passing away at Balmoral ‘made it complicated’. He added: ‘I think I heard it was the ”least planned for plan”. It was seamless, you could feel it.’
William and Kate spoke of the extraordinary public response to the Queen’s death as they met with volunteers and workers who helped in Windsor on the day of the State funeral.
It was the couple’s first official engagement since the funeral on Monday, as several senior royals returned to their duties, while continuing to mourn for the Queen.
The prince and princess arrived dressed all in black as they continue to observe the royal mourning period which lasts until Monday
The pair (pictured) have passed on their appreciation to volunteers and staff who worked on the service at St George’s Chapel on Monday afternoon
The Princess of Wales maintained the full black outfit as the family continues its period of mourning, but she smiled through her grief in order to thank the staff who ensured the Committal service was a fitting tribute to Her late Majesty
Kate waved as she left the meeting in which she and the Prince of Wales said a heartfelt thanks to the staff and volunteers in Windsor, in their first public engagement since the Queen’s funeral
Windsor Guildhall, pictured, where Kate and William are speaking to volunteers and operational staff to thank them for their work on the Queen’s committal service at Windsor Castle
Kate spoke about seeing all the infrastructure like barriers going up along the roads ‘coming back and forwards from the school run’.
The group spoke about the number of people in the crowds, with one of the logistics staff saying it was about 110,000.
William said: ‘We did not see the whole town come to a standstill. That’s what we were worried about, that it would disrupt everyone’s lives.’
Later, when one of the staff talked about how difficult the last few days must have been, he said: ‘If you flip it on its head, it is always very comforting that so many people care. It makes it a lot better. There are certain moments that catch you out. You are prepared for all but certain moments catch you out.’
The engagement is one of their first since William became the heir apparent and became known as the Prince of Wales, after the death of his grandmother and the accession of his father, Charles, to become the King.
William also inherited the title Duke of Cornwall and is now the Duke of Cornwall and Cambridge. Kate is now known as the Princess of Wales and the Duchess of Cornwall and Cambridge.