I'd say the difference is contrasty sharpness versus smooth sharpness, Japanese lenses being crisp and contrasty-sharp, European lenses being smoother and less contrasty. As to color rendition, it's been so long since I've used color film intensively, I couldn't say.
I see a distinct difference between my Fuji 6x9's 90mm lens and my Hasselblad's 80mm lens. The Fuji lens produces crisp, sharp, contrasty images. The Hasselblad produces a smoother, less contrasty image. Under a 6X loupe, negatives from the Fuji look sharper. Hands down. Does that mean the 'Blad isn't as good? No. The detail is all there, it's just not as abruptly delineated as it is by the Fuji. I prefer the Hasselblad's tonal rendition, but I won't deny for a minute that the Fuji has a fabulous lens. It's nice to have a choice, nice to own both, each camera has its purpose.