Any fire based magic or effects, including warlock mount and metamorph, will have the green color. Destro-locks use the most fire based attacks, so it would be visible the most on them.
Edit: btw, quest is no joke. You need the Grimoire 1st (rares on isle of thunder or you can buy off AH), which starts the chain. Before black temple, empty your bags as much as possible (bonus looting spree is part of it). The final fight is basically a solo heroic raid. You need pots/flasks/glyphs/etc. Destro spec is your best bet, be sure you get the enslave demon glyph and the embertap or healthstone glyph (more self healing). You have almost no room for error, even if you try to overgear. Have fun
No joke guys. I mean I'm probably a bad now that I'm 40 years old, but I was struggling pretty hard. First 10 tries were in demo spec sub 500 ilvl. That didn't go so well. Caved and went destro. Much better, but still forgot about random stuff every try. Stupid stuff too, things that would get you kicked out of a raid after the 3rd wipe. Glad it's a solo scenario or my reputation would be ruined.
In the end the fight is less about dps and more about execution. Dispells are key, had a really good try (under 20%, got excited) when the splurt-type dot ate me.
Before, I mainly had problems with the felhunters. Stupid things, but once I knew where to move the pitlord and how to catch the puppies before they found him, that was good.
Other times I just forgot to sac my imp, forgot to summon a healthstone, forgot to dispell myself on cooldown, forgot to use the pitlord heal, clicked on some damn imp and lost target --> no interrupt on cataclysm, etc etc etc.
In my last fight, I actually forgot the healthstone again. Didn't notice until running a heroic later that evening though. Didn't need it. Ember Tap & pitlord heal is plenty. Put the pitlord heal on mousebutton5 or something, and don't be afraid to stand in his breath, much easier to keep up with the dispells that way. Dispelling is probably the most important part of the fight.
Also, fire & brimstone on those fucking imps ... feelsgoodman.
What I did right:
- flask up
- buff food
- sac imp
- set kanrethad as focus target
I was horribly overgeared on my last 5 tries (545 ilvl, legendary cloak) and still managed to fuck up. But as I said, my reflexes aren't what they used to be, I'm not that much of a gamer any more.
There are plenty of youtube guides for the fight. Green fire is green fire, it burns so much hotter than regular fire. Because it's green. (would make an awesome title for a feat of strength... now that I think of it. "Because it's green.")