In 1988, she was promoted Technical Advisor in Minister of Public Works Maurice Faure's cabinet, under the presidency of François Mitterrand.

In 1993, Minister of Foreign Affairs Alain Juppé and Cabinet Director Dominique de Villepin named Colonna deputy spokeswoman.

For the following nine years, she served as the official voice of the French Republic's presidency, then left office to work as Director General of the National Centre of Cinematography (CNC) in September 2004.

From autumn 2007 until summer 2008, Colonna participated in the Commission on the White Paper on Foreign and European policy of France, led by Alain Juppé.

[3] In December 2010, Colonna joined the Paris office of international financial communications firm Brunswick as managing partner.

"[11] In February 2024, Colonna was appointed by United Nations Secretary-General António Guterres to lead an independent review group to look into accusations by Israel that 12 staff members of the United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA) were involved in the 2023 Hamas-led attack on Israel.