I've always wondered why Saiyan hair turns yellow during super saiyan transformations. I then remembered something about surpassing a characters bodily limits.
So my thought is this, the hair sticks up straight during SSJ to maximize surface area, while the hair doesn't change pigmentation in and of itself, but has it's own independent (yellow) aura of energy (Ki) bleed. All this is to prevent the overflow of Ki from destroying a Saiyans body for the duration of the transformation. This also explains the variation in hair colour depending on how much power is being used, and Why SSJ 3 grows more hair (and why it's so wasteful, it literally wastes a significant portion of the users Ki).
This doesn't explain the SSJ 4, however, nor the Oozaru, although the latter could be explained as the result of an entirely unrelated transformation that is also built into the Saiyans.
Edited by orumon
Can we divide the WM Gs by story arcs/sagas? I feel that it would be easier.