O'Hara did well enough in black and white films, but when Technicolor came along, she really shown. Her green eyes and red hair made such a statement that some dubbed her "Queen of Technicolor." But her popularity didn't just stem from her looks. She played feisty heroines who were no pushovers (until they wanted to be), often in pirate adventures like THE BLACK SWAN (1942) with Tyrone Power.
O'Hara's success in THE BLACK SWAN while on loan out to 20th Century-Fox led her home studio, RKO, to cast her in a few Technicolor pirate adventure films of their own, including THE SPANISH MAIN (1945) opposite Paul Henreid, SINBAD THE SAILOR (1947) with Anthony Quinn and Douglas Fairbanks, Jr., and the pirate-less swashbuckler AT SWORD'S POINT (1952) also featuring Cornel Wilde.
As pirate captain Spitfire Stevens opposite the King of the Hollywood swashbucklers, Errol Flynn, in AGAINST ALL FLAGS (1952), which also featured Mildred Natwick and Anthony Quinn.