Adobe Photoshop's functions for creating filled objects are producing different color output values while using the same color input value.

Photoshop stores different histogram index values (0–255) and that results in different tonal values (0–100%). Depending on the CMYK output process this bug may cause visible color differences.

These differences were primarily mentioned by Klaus Karcher in the German ECI mailing list during a discussion about rounding differences in TIFF based measurement targets.