Yeah, I wasn't too convinced that it was Yossy's real hair for the Top Secret PV. The pink colouring seemed a bit off to me. From recent pics that I've seen of Yossy, you're probably right... her real hair > wigs.
The thing with both of them right now is that their hair colour is brown. Shouldn't be too much of a problem for Yossy and extensions, but with Rika, she'd probably have to dye it black again to have the Angry look.