I use black beading on the violins I build for the inlay around the edges, in my experience ebony can be a nuisance to bend around tight corners where as most dyed softer woods are much easier to handle.
A lot of the dyed soft wood I have come across appears to be maple that has been dyed with black aniline dye which if it is not fixed properly can bleed a bit when you apply a varnish that has a strong solvent directly over it, I personally have never had problems with ebony bleeding.
The traditional way for most of the classical Italian violin makers to make a black beading is to use pear wood that has been dyed with logwood chips, if this is done properly it creates a fantastic intense black beading that is flexible, lightfast and doesn’t have any bleeding problems. The process is relatively simple; if you would like the receipt just e-mail me.
Neil.