The Queen wore a cheery cerise pink coat and bow brooch while Kate donned a Roksanda Ilincic color block dress to greet the crowds.
She said she would love to race at Royal Ascot one day but "as an amateur it's never going to happen".
"He's just lovely", she said.
If Kate Middleton were to become pregnant again, could her baby be at risk for contracting the Zika virus, especially if she were to be carrying a baby upon entering the Summer Olympic Games in Brazil?
The Duke and Duchess of Cambridge signed their special messages in front of a commemorative flag presented to the former Secretary of State Hillary Clinton by the LGBT organization Kaleidoscope Trust.
But the attractive dress - which Kate perfectly matched with a white hat - definitely broke the rule which says royal outfits must be below the knee.
To incorporate a bit of nostalgia into her look, Middleton accessorized with her bespoke Robinson Pelham earrings featuring a diamond-encrusted tear-drop, which she previously wore at her wedding in 2011.
Prince William is due to present a trophy to the victor of a race named in his honour.
She was also applauded for her Roksanda Ilincic block colour powder blue and coral dress she donned for an outdoor party on The Mall in London on Saturday, which she paired with nude stilettos and a matching clutch.
You know, as if you didn't know... "They will be there for one day this week".
Kate Middleton continued to share how sport acts as point of inspiration and motivation to keep active. "The Queen's strong health and relentless energy; her sharp wit and famous sense of humor; and the fact that the Queen remains very much at the helm of our family, our nation and the Commonwealth".
"Prince Philip and I have been shocked by the events in Orlando", the Royal Family's Twitter account posted. The publication shares about the Queen's bold look and the importance of the event.