All eyes were on Kate Middleton as she walked out of St. Mary's Hospital in London on Monday with Prince William just hours after giving birth to her third child. The Duchess of Cambridge stunned with a bright red three quarter-sleeve dress, which seemed incredibly reminiscent of the look Princess Diana chose to wear for her royal baby reveal with Prince Harry in 1984. Kate and Diana's dresses are both the same shade of crimson, and feature a white collar around the neckline. The Duchess of Cambridge also chose to pair the ensemble with classic pearl earrings like her late mother-in-law did.This is not the first time Kate has draw inspiration from Princess Diana's sense of style. She has noticeably channeled Diana's looks in on multiple occasions, including a red houndstooth suit, an all-red ski outfit and a flowing red gown.What is the royals' fascination with color red? In the documentary "The Queen at 90," Sophie, Countess of Wessex, explained that it is customary for royalty to want to wear bright colors in order to stand out in a crowd."She needs to stand out for people to be able to say 'I saw the queen,'" Sophie said of Queen Elizabeth. "Don't forget that when she turns up somewhere, the crowds are two, three, four, 10, 15 deep, and someone wants to be able to say they saw a bit of the queen's hat as she went past." According to ColorPsychology.org, the color red attracts attention more than any other color.For the reveal, Kate not only chose a dress that is a standout color, but also from one of her favorite designers. According to royal correspondent Richard Palmer, the red dress was designed by British fashion designer Jenny Packham. The Duchess of Cambridge wore Packham in both of her previous reveals following the births of Prince George and Princess Charlotte. Below she is pictured wearing Packham's in a light blue dress with polka dots for George, and a cream and yellow silk dress with a buttercup print for Charlotte.