As part of global events marking International Women's Day, up to 106 people aimed to create the largest spray-paint mural by multiple artists in a tunnel in Waterloo, south east London.
They are still waiting for confirmation that their efforts have clinched the Guinness World Record.
Organiser Rosalia Ferrara said the newly-transformed Leake Street Tunnel, which was first covered in bubblegum pink paint as a backdrop, "is looking amazing".
The participants created a series of images on the theme of "It's is a woman's world" which were then linked together as a mural.
The artists, who come from Britain and abroad, each paid a #2.50 registration fee to take part in the record attempt. All the money, including the cash donated throughout the day, is going to Breast Cancer Care.
So far £1,500 has been raised for the cancer charity.