Be aware that scanners (or more precisely, the software they use) can also do weird things. After all, photofinishers these days just scan negatives and let the software do what it does, then make digital prints. In days of yore, photofinishers made direct analog prints, but they set the parameters based on computerized analysis of the negatives (with decreasing sophistication the longer ago you go). That said, if you understand the scanner software and its color options, you can get scans with a consistent set of color settings for frame-by-frame or roll-by-roll comparisons. OTOH, sometimes you need to tweak the settings, whether scanning or making direct prints, to adjust for things like changes to the light source.
All in all, judging the color in color print films can be tricky; a lot of what you see is strongly influenced by post-negative effects (scanning, the paper used, photochemicals for RA-4 paper processing, etc.).