Wait, I am so confused now. I thought Forsythia's hair is meant to be bright green. This is not an error pony that I know of. In my opinion, she is not ugly at all, and I like her colours much better than her G3 counterpart.
Anyways, my Forsythia card has her clearly with green hair, not yellow/gold. Maybe they changed her card for the North American release. Also my Forsythia card is kinda pink, not yellow like the rest of them. Maybe they fixed her card but didn't change the pony.
I am sure its the right colour as well although I think its cute the way we each perceive the colour combinations differently - what one person likes another does not!