Robert Hardman, the Queen’s biographer, said the 85 year-old monarch was “engagingly modest” despite being the most famous woman in the world.
The author of “Our Queen”, published last year, said she would have been delighted with the rapturous reception she was to receive in Leicester.
The Queen was accompanied on Thursday by the duch*ess of Cambridge, 30, as well her 90 year-old husband, the Duke of Edinburgh, as part of events to kick-start the Diamond Jubilee tour.
Despite the attention heaped on her, Mr Hardman said the Queen remained down to earth.
“This is someone who turned down a set of stamps to mark her 70th birthday, on the grounds that it was a lot of fuss about nothing,” he told BBC Radio 4’s Today programme ahead of the visit.
“She is engagingly modest. My favourite remark she ever said was ‘I can never wear beige because nobody will know who I am’.” He did not say when or where she made the comments.
On Thursday, the Queen wore a cerise cashmere dress and coat with black trim by Angela Kelly, her senior dresser and a matching hat, also by Miss Kelly.
Royal aides said later that they were unaware the Queen had a particularly preference for her dress colours. They said she had worn hundreds of outfits in different colours.
"The Queen wears all colours. She has a Mac after all," said one source.
According to Buckingham Palace, the Queen’s design team “try and use both old and new fabrics when designing”.
In paying tribute to the Queen, Mr Hardman said: “Clearly she is the most famous woman in the world, I think that goes without question these days. But way beyond that, there is a sense that she is this constant in national life.
“To other countries around the world she is extraordinary. I think perhaps we take her slightly for granted here because we are so used to her. It is the fact that throughout it all, she is exactly the same character.”
A spokesman for Buckingham Palace declined to comment.
