To explore the effects of geometric features on the color similarity perception of displayed three-dimensional (3D) tablets designed by color 3D modeling techniques or printed by color 3D printing techniques, two subjective similarity scaling tasks were conducted for color tablets with four shape features (circular, oval, triangular-columnar, and rounded-cuboid shapes) and four notch features (straight V, straight U, crisscross V, and crisscross U shapes) displayed on a calibrated monitor using the nine-level category judgement method. Invited observers were asked to assort all displayed samples into tablet groups using six surface colors (aqua blue, bright green, pink, orange yellow, bright red, and silvery white), and all perceived similarity values were recorded and compared to original samples successively. The results showed that the similarity perception of tested tablets was inapparently affected by the given shape features and notch features, and it should be judged by a flexible interval rather than by a fixed color difference. This research provides practical insight into the visualization of color similarity perception for displayed personalized tablets to advance precision medicine by 3D printing.