11/13 Nichols - Goku's Super Saiyan 4

In the DragonBall realm, only the greatest warriors survive. This is the embodiment of one of the anime series' greatest warriors and protagonist, Goku. In the anime series, starting with the original anime Dragonball, Goku is an alien warrior, otherwise known as a saiyan, that is sent to Earth as one of the last remaining  of his species. Through the series, Goku makes friends, trains with some of the finest fighting master's in the universe, and soon after has to face some of the fiercest foes in the galaxy. Goku ages and moves on to start a family in the second DragonBall series, titled DragonBall Z, where he continues to fight and attain levels of power thought unreachable by any saiyan. Through his fights, he conquers his ability to transform into the mythical Great Ape, a legendary saiyan exclusive transformation, that allows him to defeat some of his early opponents. Not long after he attains the legendary Super Saiyan form, an even more powerful saiyan ability reserved only for the strongest of saiyan fighters. The transformation gives Goku a glowing yellow aura, golden blonde spiked hair, green eyes and a massive boost in power level, but this is only the beginning of his abilities.

Through the Dragonball Z series Goku attains levels unimaginable to any of the saiyan warriors, surpassing Super Saiyan not once, but twice. Goku's Super Saiyan 3 ascends him to incredible new heights with an intimidating new look, including a lightning infused gold aura, glowing blonde hair curled down his back and strangely no eyebrows. Many assumed this would be the last of the Super Saiyan transformations after the DragonBall Z series ended, but the journey continues on in DragonBall GT, the continuation of the popular series. As Goku said in the series, "That's right, you may have anticipated my attacks so far, but you have no idea what I am capable of now... and what you don't know... could hurt you."

GT brings with it Goku's most unique physically altering transformation. In a fight with baby Vegeta, Goku's Super Saiyan abilities fall short and Goku is forced to resort to transforming into the legendary Golden Great Ape form. At his power level, Goku is able to control and override his Great Ape abilities and shrink down to human size, introducing Super Saiyan 4. The new transformation reveals Goku in all red fur, black/red spiked hair, golden eyes with red trim and of course, a flaming aura.

The most shocking of these changes is the color transition from a glowing gold to a dark red and a return to black hair. The remainder of hair might be from the shift from ape to human, but the shift from gold to red and black seems to have little explanation. What stands out to me is the return to black hair, the original color of Goku's spiked hair. It's interesting because when Goku normally shifts from ape to human he returns to his normal self, but at such a power level his saiyan powers may have fused with his ape abilities, forming an ultimate combination of his abilities. The human transition could then be a slight return to his former self with black hair, but that doesn't provide much to explain the red flaming aura or the red chest and arms. 

One DragonBall GT blogger under the username SUPER SAIYAN HISTORIAN wrote "Why does Super Saiyan 4 have pinkish/reddish fur when it clearly should be gold. Even though I like the look, it is still wrong." The blogger might have hit the nail on the head here. As far as consistency goes. the transition is unexplained. It sure looks intimidating, but for many, it's unclear how this happened. The show doesn't really offer an explanation, nor do any fan sites, but maybe the solution is more simple.

Red and black are colors that more often than not portray dark, intimidating figures and carry with them a sense of fear and dominance. Red is often associated with intense strength, energy and passion, bringing with it even fire and maybe even a bit of rage. Goku's fire aura and red fur coat might be a reflection of his inner passions burning into his outer being, especially since this new power level is an embodiment of all these powers. Black is often also associated with power and strength, but also mystery, fear and very simply an absence of color. This might be a way of symbolizing the idea that Goku's strength is seemingly boundless and his range of capabilities still remain unknown. With this in mind, the black and red hair combination provides Goku the mysteriousness necessary to intimidate his opponents and the power to back it up. 

Sources:
http://dragonball.wikia.com/wiki/Super_Saiyan_4
http://www.gamefaqs.com/boards/720091-dragon-ball-z-battle-of-z/66844535
http://dragonball.wikia.com/wiki/User_blog:Super_Saiyan_Historian/SUPER_SAIYAN_LORE
http://www.color-wheel-pro.com/color-meaning.html
http://www.bourncreative.com/meaning-of-the-color-black/
http://dragonball.wikia.com/wiki/Wilderness_Survival!_A_Moonlit_Night_Awakens_Gohan!