Well, I'm more into colours than the items themselves so I've been trying to dye with multiples of a single colour with a fourth different one etc, because dying it black never sat right with me, it feels like the colours gets dull... So What do you do? You PAINT THEM WITH THREE BLACK DYES, (a splash of white might've been involved), AND VOILA! I Call it obsidian purple, the most expensive paintjob currently for sale ingame. (Excluding pre-nerf dye, please don't bash me).
I do that also quite often. Preferably on dervish cause the cloth armors tend to come out very nice in colour