Markle wore a hat by Stephen Jones and suede Manolo Blahnik stilettos, both within the same colour tones as her Ralph Lauren dress.
The Duchess of Sussex stepped out with the Duke of Sussex in a black scoop-neck dress, black stiletto heels and a black clutch bag.
The newlyweds greeted the Archbishop of Canterbury, Justin Welby, ahead of the christening service and Meghan, who shot to fame as Rachel Zane in legal drama Suits, was caught on camera giggling as she greeted the man who officiated her wedding in May.
Fittingly, Meghan Markle arrived wearing a forest green pencil dress by Givenchy which featured pocket detailing, while holding a tan leather tote.
Doesn't Meghan looks stunning! .
Meghan, Duchess of Sussex, Prince Harry, Duke of Sussex, Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge watch the RAF flypast on the balcony of Buckingham Palace.
"I think it looks very smart".
The Duchess of Sussex joined senior royals at Westminster Abbey in a custom Dior, a day after being panned for wearing "drab" green for Prince Louis' christening.
For 100 years the RAF has defended the skies of Britain, preventing conflicts, delivering aid and combating cyber threats while working in partnership with other services.
The couple met RAF servicemen and women, charity representatives involved in the RAF100 Appeal, RAF Veterans and Civil Service personnel involved in the Centenary celebrations.
The royal couple with also meet with young people interested in coding when they visit the startup hub Dogpatch Labs in Dublin 1.
Harry and Meghan's engagements will include official meetings with Taoiseach Leo Varadkar and President Michael D Higgins.
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