Data integrity bug: Illustrator 30.3 changes CMYK swatch values after pasting clipboard bitmap image and reopening file
Product: Adobe Illustrator Desktop
Version tested: 30.3
Document color mode: CMYK
Issue type: Data integrity / color swatch value corruption
Summary:
Adobe Illustrator 30.3 reproducibly changes CMYK swatch values after a bitmap image from the system clipboard is pasted into a CMYK document. The issue appears after saving, closing, and reopening the .ai file.
Steps to reproduce:
- Create a new CMYK document in Illustrator 30.3.
- Create a CMYK swatch, for example C10 M10 Y10 K0.
- Paste any bitmap screenshot/image from the system clipboard into the document.
- Save the .ai file.
- Close the file.
- Reopen the file.
- Check the CMYK swatch value.
Actual result:
The CMYK swatch value changes from C10 M10 Y10 K0 to approximately C9.77 M9.77 Y9.77 K0 after reopening the file.
Expected result:
The CMYK swatch value should remain exactly C10 M10 Y10 K0. Pasting a bitmap image from the system clipboard should not modify existing CMYK swatch definitions.
Additional observations:
- The issue is reproducible in Illustrator 30.3.
- The issue is specifically triggered by bitmap images pasted from the system clipboard.
- If no clipboard bitmap image is pasted, the CMYK swatch value does not change.
- CMYK values such as 0%, 50%, and 100% do not appear to change.
- Values such as 10% change to approximately 9.77%, which suggests a possible unintended 8-bit quantization or percentage remapping.
- This is not just a display issue. The saved file reopens with changed CMYK swatch values.
Impact:
This is a serious print/prepress data integrity issue. It can silently alter exact CMYK swatch values, brand colors, and production colors in saved Illustrator files.
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This bug is very serious and very easy to reproduce. It causes inconsistencies in the CMYK color values of a file before and after saving, affecting the consistency of output and printing color accuracy.