Goku & SSJ Goku (release!)

[bashscrazy]

Hmm yes you're right. But my guess for that is if you see at the beginning it's like his base form colours even though he's super saiyan. That's because he is in his full power super saiyan form where he mastered it so it doesn't drain his energy while staying in the transformed state. When he and Cell are no longer warming up, he powers up, the aura obvs will make it yellower, but once the aura disappears, it maintains a yellowish tint.

Either that, or it's because different animators made different episodes and they used different colour palette's.

EDIT:
These are screenshots from my dbz episodes

episode 177 - before power up (Click to View)

episode 178 - after power up (Click to View)

You can see the difference in the wristbands, shoes and undershirt as well as they grow brighter with the power ups.
This is what I tried to emulate in my different versions of Goku I am making.

So it can be either theory. since they are different episodes.