Yeah, color paper is graded. However, the grades are not numbered like in graded BW papers, but they have fancy names. Kodak Portra Endura was lowest in contrast - IMO, this is the NORMAL contrast, like grade 2. It was discontinued in 2006. Then there were Supra Endura and Ultra Endura left; Supra Endura being a little higher in contrast than "normal" -- maybe something like "grade 2 1/2", and Ultra Endura being even higher -- like "grade 3".
Fuji's Crystal Archive is about the same in contrast as Supra Endura.