Beta Fractal Capacitor and Matching Dyes
Hmmm… what about the straight ‘blue’ dye? It’s quite dark and from what I remember it seems a close match to the cloth of the capacitor.
Midnight ice is very nearly black with a blue tint, that works for most things!
Here is a dye list with swatch colors:
http://flufffactor.wordpress.com/gw2-dye-list/
Note that the dye can appear slightly different depending on what it’s put on; cloth, metal, leather, feathers, etc. You can preview a dye if is in your bags or if you have a link in chat. Links can be obtained on gw2spidy.com