I used CC spf 50 in fair. I have very light skin with pink undertones and fair is good for me. I always go with lightest shades offered and sometimes they're not light enough...so yes, fair is more for a porcelain skin tone.
I'd like to add, this foundation is very thick, and needs some work to apply. It does cover well if that's what you want. went back to PTR un-wrinkle foundation spf 20 for the effortless application, and dewy, luminous finish. I only bought IT CC for the high spf.