Both Goku SSJ4 and Vegeta SSJ4 have black hair before they fuse. However, Gogeta SSJ4 have red hair then. When other fusions happen, the merged warrior has the combined hair of the individual warriors (Gotenks, Vegito) Why does Gogeta SSJ4 have red hair then? It's just that Gogeta, with his amazing power, red hair, and blue eyes seems to be on a whole different level than Super Saiyan 4.
It's all non-canon, so fuck it, anyone could say he's Super Saiyan 5 and it wouldn't matter. Dragon Ball GT introduced the Super Saiyan 4 form for Goku, Vegeta and Gogeta, and it stood out due to its weird hair color and aesthetics. And for the in universe reason.
Super Saiyan 4 is unique to every user, at least in GT's continuity. The only 3 GT SSJ4's are Goku, Vegeta, and Gogeta. And they all look different from each other.
Goku has black hair and a certain shade of red. Vegeta has a different shade of red and brownish hair. And Gogeta also looks different.
On Dragon Ball - General, a GameFAQs message board topic titled "Why is Gogeta SSJ4 hair red?". Today we will talk about super saiyan 4 Gogeta and the reason why he has red hair instead of black hair in dragon ball GT. We will go through 2 different the.
Design wise its because Gogeta looked almost exactly like goku and the black hair would have made it so in story theory as to why, I have been pondering it and i believe its due to the magical properties of the fusion dance having a unique affect when mixing with SSJ4. Their fusion failed showing Fat Gogeta, in his base form, revealing that his hair was black and not crimson red. 0 RustlingAlarm57 2/4/2018 Thats also true thats why trunks hair is the most annoying inconsistic thing ever in dragon ball 0 Gavinrios 2/4/2018 But you've got to admit Crimson Red hair looks awesome on SSJ4 Gogeta.
Why is super saiyan 4 gogetas hair red? The obvious answer is that he needed to look different from super saiyan 4 goku so they made his hair color lighter. For my head (non)canon I like to think gogeta was genuinely super saiyan 4 and goku and vegeta weren't able to fully go super saiyan 4. It is like goku having yellow aura but black hair.
Why is SSJ4 gogeta hair red? The reason why is because Akira Toriyama, when he is drawing and coloring, doesn't check the actual colored pictures. Thus, showing that this is a coloring mistake, and not his actual hair. Another reason to show that this isn't his actual hair is when Goku and Vegeta fused against Janemba.