I really wanted to draw something colored and with a bg, because a lot of people asked me why I don't do it. Well, I think it is time I learn
I did this pic using the mouse, because at the time I didn´t have a a graphic tablet... it was a lot of work.
I think I won't color nothing for the next 3 months and I'll continue with my lineart works (I love them because I don't need to use colors and I already have the sketches of Baftis and Cozbinaer).

I dedicate this drawing to my great friend (and great DM) Marco Formaggio . Thanks Marco for making me and my friends despise this guy so much .

This is the ultimate and colored version of the picture of this demon prince (lineart [link]). He is my favorite tanar'ri lord (together with Malcanthet) and he is the demon of fear, darkness, shadows, secrets, mirrors and tyrants.

References:
by the great Wayne Reynolds [link]
from the Book of Vile Darkness [link]

Here is what I found on the net about him:

Graz'zt is one of the handsomest of the demon lords, at least by human standards. Standing nine feet tall, he appears as a lithe, muscular humanoid. His skin shines like polished obsidian, and his eyes glitter with malevolent green light. He has yellowed fangs, pointed ears, six small black horns half-hidden amid his thick black hair and six slender fingers decorating each hand. These fiendish traits are apparent, regardless of whatever form Graz'zt chooses to take. He is considered the comeliest demon in the Abyss, and dresses in the most expensive and elegant finery on the entire plane.

Wielding an acid-drenched greatsword in one hand and a profane tower shield in the other, the Dark Prince is a veritable killing machine when loosed upon the hordes of the Abyss. What's more, he has a vast reportoire of spell-like abilities at his disposal, making him a deadly magical opponent as well. Graz'zt's greatest weapons, however, are his mastery of seduction and guile. He entertains the notion that he is the most cunning and intelligent creature in the Abyss (even more than the mighty Demogorgon and the wise Dagon); indeed, there are few who could possibly contest such a claim.

The Dark Prince is a deeply sexual, erotic being. He is known on many worlds only in legend, as a dark figure who visits witches and sorcerers, granting them sexual favors as well as magical powers. As a result, his female consorts have populated the multiverse with a depraved host of half-fiend children. Some learn of their father's identity and delve into the Abyss, hoping to usurp his power. His dark elf son, Athux, leads Graz'zt's demonic army, while his daughter Thraxxia serves as a private assassin.

For a time, Graz'zt was trapped on the Material Plane's world of Oerth by the witch-queen Iggwilv, who used his insight to elevate her own power. Eventually, however, she succumbed to the Dark Prince's charms, and their story was made infamous by the product of their romance: the vile demigod Iuz. Graz'zt ultimately returned to the Abyss, but rumors abound that he did, in fact, fall in love with his captor.

Ancient texts claim that Pale Night is the mother of Graz'zt, Lupercio, and Vucarik in Chains, which would also make him related to those demons. The demoness Rhyxali is rumored to be his sister.

Through his own schemings and mischief, Graz'zt has become the chief enemy of Waukeen, a goddess of wealth and merchantry. During the Time of Troubles, the deity bargained for safe passage to the Outlands across Zelatar with information regarding a secret horde of treasure. Graz'zt readily accepted the offer, but betrayed Waukeen as soon as she arrived in the Abyss. His goal was to usurp her power. Imprisoned in the Argent Palace, the goddess was forced to witness profane celebrations held in her honor. In the end she has been resqued by a group of brave adventurers.

But even the wrath of a god cannot compare to the hatred and spite of the Dark Prince's chief rivals, Demogorgon and Orcus. The violence of the eternal war between these three demons rivals that of the Blood War, and costs them unthinkable resources that could be put to use in the battles against the baatezu. Graz'zt covets Demogorgon's title as the Prince of Demons above all else, and throws army after army at his most hated enemy in hopes of claiming it.

Graz'zt is always attended by six powerful lamias, and his marilith escorts, Unhath and Reluhantis, are never far from his side. When at his palace, the Dark Prince keeps many attractive demons at hand, to feed his ferocious sexual appetite. Bodaks and similar horrors are the only other occupants of the Argent Palace's labyrinth of mirrors.

Edit: I changed the pic a little using the Wacom.