Color sequence choice is one of the factors that affects the quality of printed color reproductions. The ideal sequence is largely dependent upon ink transparency and ink trap efficiency, both of which vary according to the printing system. Definitive research into the color sequence issue has been hampered by the experimental noise that occurs when running separate press trials of different sequences. A novel method, using a 5-color press, of studying the CMYK vs. KCMY color sequence choice for wet-on-wet offset lithography is presented. The first and fifth units of the press are used for black test images that print, respectively, with corresponding CMY test images located on the intermediate units. Noise-free pairs of CMYK and KCMY samples were thus obtained. The subsequent analysis revealed that the CMYK sequence produced both a higher Dmax and noticeably more neutral dark tones than the KCMY sequence. It is recommended that the experiment be repeated to confirm the quality superiority of the CMYK sequence, and then this sequence be unambiguously incorporated into the ISO 12647-2 standard, as well as into such related specifications as SWOP and GRACoL.