Chloë Grace Moretz has been a regular attendee at high-profile events, including Vanity Fair's Oscar Party in the past.

However, due to the vast number of celebrities and attendees at such events, specific details about an individual's appearance might not be readily available in my database.

For precise information about Chloë Grace moretz's attendance or any particular details regarding her appearance at the 2019 Vanity Fair Oscar Party.

I suggest checking entertainment news archives, red carpet galleries, or reliable celebrity news sources that cover event highlights and red carpet appearances from that time.

These sources usually provide detailed information about celebrities' outfits, appearances, and noteworthy moments at such events.