Improved achromatization of phase mask coronagraphs using colored apodization M. N’Diaye, K. Dohlen, S. Cuevas, R. Soummer, C. Sánchez-Pérez and F. Zamkotsian A&A, 538 (2012) A55 Published online: 01 February 2012 DOI: 10.1051/0004-6361/201117661