For the royal family, the annual "Trooping the Colors" has always been a family affair. Princess Kate Middleton made the event even more meaningful this year when she decided to attend, after retreating from public appearances following her cancer diagnosis. The mother-daughter coordinated outfits with her daughter Princess Charlotte were a show of family unity in front of the cameras.

Princess Charlotte and Princess Kate arrived at Buckingham Palace together for King Charles III's birthday celebration early in the afternoon on Saturday, June 15; the two wore coordinated outfits, but not in the same copy-and-paste fashion. Kate Middleton wore a white Jenny Packham ribbon dress with a contrasting navy bow and a Philip Treacy hat in the same color scheme. Beside her, Princess Charlotte wore a navy dress with white ribbon detailing, almost the exact opposite.

Her mother, Kate Middleton, kept the ribbon to an exaggerated embellishment on the lapel of her knee-length dress, while Princess Charlotte wore a double layer of ribbon. Her hair was styled half up, half down with a white ribbon fastened at the back. Meanwhile, the front of her dress was decorated with a sailor collar and a matching white ribbon tied in the center.

Even when it came to shoes, mother and daughter took a similar but not identical approach. Kate Middleton wore white pointed-toe pumps with high heels befitting the head of a family. Princess Charlotte also wore white shoes, shaped like a dainty doll-like mary jane; their outfits can be seen in detail in a behind-the-scenes video posted on the Prince and Princess of Wales' official Instagram account.

Working with stylist Natasha Archer, Middleton chose to coordinate with her daughter, perhaps by design. Last year, Princess Kate wore a bright green dress, while Princess Charlotte was dressed in white and red. It is poignant that Kate and Princess Charlotte appear for the first time in six months and closely reference each other through their dresses after the difficult journey of cancer treatment.

Coordinating the family was not left solely to Princess Kate and Princess Charlotte. Prince George and Prince Louis continued the navy and white theme, wearing suits, white shirts, and royal blue ties. Prince William was the only member of the family to dress outside of this palette: following tradition, Prince William wore his formal military uniform.

While Prince William entered Buckingham Palace on horseback, Princess Kate joined her three children in a glass carriage. According to reports, spending time with Charlotte, George, and Louis was the main reason Kate Middleton surprised the world and attended this year's Trooping the Color.

The opportunity to bring the whole family together again will be rare in the future: in a statement, Princess Kate said that her health is "progressing" but that she still expects to be in treatment for a few more months. So summer outings, with or without color-coordinated mother-daughter outfits, will be limited in her return to royal life.