you may be interested in this, as I recall you were playing around with various copper salts a while ago,
unfortunately I cant access the full paper, nevertheless...….it shows there are alternative blue emitters, even though they maybe more expensive than the conventional ones,...……...always worth knowing
Chlorine‐Free Pyrotechnics: Copper(I) Iodide as a “Green” Blue‐Light Emitter
Prof. Dr. Thomas M. Klapötke
, Dr. Magdalena Rusan
, Dr. Jesse J. Sabatini
First published: 09 July 2014|
https://doi.org/10.1002/anie.201405195|
abstract - The generation of blue‐light‐emitting pyrotechnic formulations without the use of chlorine‐containing compounds is reported. Suitable blue‐light emission has been achieved through the generation of molecular emitting copper(I) iodide. The most optimal copper(I) iodide based blue‐light‐emitting formulation was found to have performances exceeding those of chlorine‐containing compositions, and was found to be insensitive to various ignition stimuli.