A black necklace was placed under the pointed collar of the white dress shirt, coinciding with the main color scheme of her ensemble.

Source: https://www.dailymail.co.uk/galleries/article-11834959/Priscilla-Presley-makes-red-carpet-debut-Lisa-Maries-passing.html?ns_mchannel=rss&ns_campaign=1490&ito=1490

Acceptable dress standards for the blokes are a suit or blazer, tailored trouser pants, a collared dress shirt with a tie or bow tie and dress shoes.

Source: https://www.dailymail.co.uk/femail/fashion/article-12717881/Melbourne-Cup-Dress-Code-2023-not-wear-updated-rules-shorts-allowed.html?ns_mchannel=rss&ns_campaign=1490&ito=1490

Reddit user Aneriox shared the images on r/DCEUleaks, which show Phoenix's disheveled Arthur Fleck in a dirtied suit resembling Dwight Schrute's usual brown suit and yellow dress shirt combo.

Source: https://www.cbr.com/joker-2-joaquin-phoenix-dwight-schrute/

Villalobos is wearing a blue dress shirt and dark slacks.

Source: https://abcnews.go.com/US/wireStory/oregon-courthouse-security-video-shows-escaping-defendant-97779776