The bright colors on the socks he wore is in celebration of LGBT pride while the Islam symbols on it (the star and crescent shaped moon) are in celebration of Ramadan. It was probably his way of giving a nod to both celebrations. Trudeau’s wife, Sophie Grégoire Trudeau, and their children Xavier and Ella-Grace, were present at the parade and waved a rainbow flag (one of the symbols of the LGBT community).
In his speech, Trudeau declared:
“This is all about including people. It’s all about how we celebrate the multiple layers of identities that make Canada extraordinary and strong, and today we celebrate with the entire LGBTQ community.”