Methods To Intentionally Tone Silver Blue?

Does anyone know a good method to tone silver blue?
(Specifically blue?)

I'm going to make a scale model which involves machined silver pieces, some of which will need blue color. Paint won't look good, blue AT will be superior both in aesthetics and durability.

I've searched on the net and seems like the best method I found is by anodizing silver in NaOH solution + Sulfur mixture with low voltage for better controls, as demonstrated in the following video:



Has anyone who ever experimented with AT found a better way to reliably produce blue AT?

Thanks.

N.B.:The silver will come from junk coins though so it's in a sense still relevant to ask this question here in a numismatic forum