Thanks for the guidance. I’ve submitted the report. Feedback ID: FB21014376 The package includes: ColorSyncProfileTest project Dummy LUT ICC profile Working matrix ICC profile Steps to reproduce Terminal output showing fallback ICC behavior Let me know if you need any additional diagnostics or system traces.

Hi, Thank you for the response. Can you please clarify the following? 1. LUT-based display ICC profiles did load and function on macOS 10.7 through macOS 13, including profiles generated by DisplayCAL, X-Rite i1Profiler and ArgyllCMS. • They were selectable in Display Preferences • ColorSync showed the LUTs in A2B0/B2A0 • Measurement reports confirmed the LUT corrections were applied • This behavior regressed starting around macOS 14 2. If LUT profiles were “never supported”, can Apple confirm: • Why they worked for over a decade? • Why ColorSync accepted them? • Why the system UI allowed activating them? • Why professional color workflows relied on them successfully? 3. If LUT profiles are now intentionally unsupported, can Apple provide: • An official statement • Updated developer documentation • Recommended alternative APIs or workflows for users needing high accuracy calibration? Given how many professionals rely on LUT-based profiling, this is critical information. FB21014376 Thank you.

Hi, following up on this issue. The problem persists in macOS 26.1 and the system still loads fallback profiles instead of LUT ICC profiles. Is there any update on the engineering review? Feedback ID: FB21014376