and that was in the anime. The anime takes a lot of creative liberties with the series and is the cause of a lot of inconsistencies. It is an established fact by manga canon that all Saiyans have black hair, dark eyes, and their hair doesn't grow.
You know, in DBGT Goku was able to magically change his shoes and belt while transforming in super saiyan 4, and Vegeta's fingerless gloves became full gloves just as magically... I'm so glad you have avoided that crap in your comic...
As far as I know Fusion is a "TECHNIQUE" which enhances Chi of two beings after "COMBINING" them & as a result/side-effect of which you get new clothes which is the case with both Fusion & SSJ Transformation..! Piccolo also creates Clothes from nothing..!
The reason why like Malik's Brain is how amazingly he created the concept of Reiki (in Aladjinn Saga) which can easily explain all these magical sort of stuff happening like creation of clothes. Reiki is kinda like the basic unit of chi. So probably sub-consciously SSJ4 transformation creates new clothes like how Piccolo does..!
Well they couldn't make Goku Naked so they had to come up with something..! It would have been better if at the starting of DBGT Goku wore expandable clothes made by Bulma..! This problem would have been averted..! Hehe..!