Sotheby's, File, Associated Press
FILE- This undated file photo provided by Sotheby's shows a 1955 painting by Mark Rothko, "Untitled (Yellow, Orange, Yellow, Light Orange)," from the estate of Rachel "Bunny" Mellon, a noted horticulturist, philanthropist and Listerine fortune heir. The painting could sell for $20 to $30 million when it is auctioned by Sotheby's in New York Monday evening Nov. 10, 2014.

NEW YORK — Two boldface names — Rothko and Mellon — are getting prominent attention at an auction Monday of post-war and contemporary art.

Two Mark Rothko paintings owned by Rachel "Bunny" Mellon are among the offerings of Sotheby's evening sale.

Mellon was heir to the Listerine fortune, a noted horticulturist and widow of philanthropist Paul Mellon. She died in March at 103 at her Virginia estate.

"Untitled (Yellow, Orange, Yellow, Light Orange)" could sell for $20 million to $30 million. "Untitled," created 15 years later, has a pre-sale estimate of $15 million to $20 million.

On Tuesday, Sotheby's is offering a third Rothko. "No. 21 (Red, Brown, Black and Orange)" was purchased by art benefactors Pierre and Sao Schlumberger directly from Rothko's estate. It could bring over $50 million.