She may have sung that diamonds are a girls best friend, but Marilyn Monroe proved that true brilliance comes from within. In Gentlemen Prefer Blondes (1953), she lit up the screen as Lorelei Lee Marilyn Monroe's white Travilla dress made of silk satin with a slight train and detachable bow, identical to the pink 'Diamonds Are A Girl's Best Friend' dress. For Gentlemen Prefer Blondes, 1953. Did you know that Marilyn Monroe's Diamonds Are a Girl's Best Friend look in Gentlemen Prefer Blondes almost wasn't pink at all? Originally, Travilla designed a dazzling $4,000 showgirl costume covered Marilyn Monroe pink dress in 'Gentlemen Prefer Blondes' = iconic.