Yes, CD-n (CD-2, CD-3, CD-4, etc.) are Kodak color developing agents. They've got very long chemical names that would probably be meaningful only to chemists. The photochemical suppliers that sell them (at least, to the general public) don't use the full chemical names; they sell them as CD-3, etc., so just look for that. The last I checked, Art Craft had both CD-3 (used in RA-4, E-6, and ECN-2) and CD-4 (used in C-41).