“Disappointment and anger were my reactions,” upon learning of the harassment accusations against Mr. Meier, Mr. Soloviev said. “I didn’t see it coming. But his firm did their job and gave us a beautiful building.”

At first glance, the tower at 685 First Avenue, which has 148 condos and 408 rentals, is a classic Solow project. On a site that spans the entire block from East 39th to East 40th Streets, it has a reflective black-glass facade, like most of his apartment towers, including 265 East 66th Street, a rental at Second Avenue, and One East River Place, on East 72nd by the F.D.R. Drive.

It even resembles Solow’s 9 West 57th Street, the sloping office tower that once commanded some of the highest office rents in the city, though much of it is currently vacant.

Mr. Meier, who is known for almost always designing white buildings, rolled his eyes when asked why he hadn’t deployed his signature look. “I have to be honest with you,” he said, before looking in the direction of his client.

“I just feel from the outside it is very strong, almost like marble, but from the inside you can’t tell it’s black, because it’s perfectly translucent,” Mr. Solow said of his favorite building color.

If Mr. Solow, who lives nearby at 860/870 United Nations Plaza, is remembered for any buildings, he said he hopes they will be 9 West 57th and 685 First. And the deep-pocketed developer, who in 2017 was ranked 140 on the “Forbes 400” list of the richest Americans, with $4.7 billion, seems intent on shaping his legacy carefully.

In February, he traveled to a quarry in Italy, accompanied by Mr. Soloviev, to personally choose travertine panels for the walls of 685 First’s soaring 30-feet-tall lobby. Workers at the site said Mr. Solow calls every day to check on his tower’s progress.