Meghan, who is expecting her first child with husband Harry, opted for a Club Monaco dress in a strikingly similar shade as she visited the Hubb Community Kitchen to meet survivors of the Grenfell Tower tragedy.
Rochelle White explained the pair's differing looks.
"Kate's outfit has a look of sophistication to it. With the sheer black tights and finished off with a high neck jumper or dress, it gives off a classy look," Rochelle told FEMAIL.
"This is a classic Kate look I think. Sleek, stylish and represents her and her style. She added a simple black bag that finished off the look.
"Meanwhile with Meghan’s outfit I feel that this was a lot more relaxed and fun. With the purple on purple or burgundy colour it really compliments her skin tone.
"I think that Meghan has chosen an outfit that trendy, fun and a good representation of her and her growing style into the royals."
See Kate's best baby bump fashion below: