Why the change in Tao's clothing?

Reviewers have called him the worst-dressed character in kid's cartoon history, but I quite like the simple "diaper and poncho" combination, as well as that elaborate anklegear and footwear.

But for the Second Series, it's changing a bit to feature undergarments as well. Tao seems to now wear a shirt underneath his poncho, not to mention "shorts" on his legs as well - what's with that?

Why? Is it cold in China and Spain, compared to South America? I figured he'd need more layers to keep warm in those cold climes.

I haven't seen any changes to any of the others' clothing, but feel free to correct me.

Star Trek: Multi-spectral subspace engines
SF Debris: So the shuttle is powered by rainbows?