Blue Pyrotechnic Flames – The Ultimate Illuminant Challenge
Blue-colored flames have often been considered the most challenging to produce pyrotechnically. Recent work by IPS members sheds new light on this fascinating topic. Copper(I) bromide has been proposed as a blue-light emitter in chlorine-free formulations. And, importantly, the spectral properties of CuX species (where X is a halogen atom) have now been investigated.

Copper(I) Bromide: An Alternative Emitter for Blue-Colored Flame Pyrotechnics
DOI: 10.1002/chem.201502752
Dominykas Juknelevicius, Eero Karvinen, Thomas M. Klapötke, Rytis Kubilius, Arunas Ramanavicius, and Magdalena Rusan

Spectral Investigation and Color Properties of Copper(I) Halides CuX (X = F, Cl, Br, I) in Pyrotechnic Combustion Flames
DOI: 10.1002/prep.201500231
Ernst-Christian Koch