This beautiful creature is deserving of only the most magnificent of hues. I would suggest blending in soft, subtle shadows of ivory and cream in order to create depth and definition. The shining gold horn can be accented with a warm, honey-toned yellow to bring it to life. The mane and tail could be illuminated with flecks of silver and grey in order to give them a twinkling, almost magical quality. Complete the image with strong, dark lines of black and charcoal to really emphasize its regal nature, and also give it an otherworldly aura. Use of an airbrush will help to blend in some of the harsher lines and really complete the look of this majestic creature.