LR Classic on M4 IMAC with GPU Accel On has incorrect color display for photos

Report · Apr 22, 2025

Latest Lightroom Version (V14.2)

M4 IMAC, 32GB Memory, Running Latest OS (Sequoia 15.4.1)

I am currently dealing with an issue where having my GPU On is causing the colors in Lightroom to shift and cause the color to be innaccurate on screen VS. what is exported. I have narrowed this issue down to Lightroom alone, as photoshop and preview both show the correct image colors, and my iPhone also shows the image colors correctly compared to photoshop and preview.

When I turn the GPU Off in Preferences, the colors revert back to being accurate. Unfortunately, Lightroom is not worth using with it Off, as the resolution of the image I am editing drops to a blurry mess when I adjust anything in Develop.

I have tried changing my ICC profiles through the defaults on the IMAC, and I have also calibrated the display using my SpyderX Pro. These affect the display as they should, but the Lightroom images still display innaccurately.

Fairly certain there is something going on between LR and the GPU in the M4 IMAC...

The attached screenshot shows the difference in the photo colors / saturation / tones, obviously it is a little more noticeable on my end with other photos and seeing the difference up close and also on my phone. (I know the phone will always show colors a little different, but this issue is only occuring on my IMAC and not on my windows PC)

Report · Apr 22, 2025

As a diagnostic, follow these steps exactly for determining if there's an issue with the display profile assigned to your display:

https://www.lightroomqueen.com/how-do-i-change-my-monitor-profile-to-check-whether-its-corrupted/

If you've already done this, try those exact steps again just to be sure.

Report · Apr 23, 2025

Tried this on a fresh startup of the imac, and the issue still persists. The display adjusts to the ICC profile changes, but within lightroom, it seems that there is an oversaturation and hue shift specifically in the reds, oranges, and yellows with the GPU on..

the greens, blues, and purples match more closely, both in the sRGB icc profile and my SpyderX calibrated profile.

And then still, when I turn the GPU off in preferences, the colors are exactly matching between LR and my exported photos.

I am confident it is a Lightroom specific bug with the GPU, because in photoshop, after effects, and other programs, the colors are correct.

Report · Apr 23, 2025

Hi, if you continue to experience the same behavior after trying the steps suggested by Johnrellis, go to the Help menu in Lightroom Classic, then System info, and copy the text. You can share the info with us by either pasting it here or pasting it in a text file and sharing the file with us.

Thanks,
Nikunj

Report · Apr 23, 2025

Lightroom Classic version: 14.2 [ 202502071718-3869eef7 ]
License: Creative Cloud
Language setting: en-US
Operating system: Mac OS 15
Version: 15.4.1 [24E263]
Application architecture: arm64
Logical processor count: 10
Processor speed: NA
SqLite Version: 3.36.0
Built-in memory: 32,768.0 MB
Dedicated GPU memory used by Lightroom: 1,543.6MB / 21,845.3MB (7%)
Real memory available to Lightroom: 32,768.0 MB
Real memory used by Lightroom: 1,873.5 MB (5.7%)
Virtual memory used by Lightroom: 411,941.7 MB
Memory cache size: 249.2MB
Internal Camera Raw version: 17.2 [ 2155 ]
Maximum thread count used by Camera Raw: 5
Camera Raw SIMD optimization: SSE2
Camera Raw virtual memory: 493MB / 16383MB (3%)
Camera Raw real memory: 995MB / 32768MB (3%)

Cache1:
Final1- RAM:266.0MB, VRAM:29.0MB, _Z5A8345.CR3
Final2- RAM:189.0MB, VRAM:0.0MB, _Z5A8313.CR3
NT- RAM:455.0MB, VRAM:29.0MB, Combined:484.0MB

Cache2:
m:249.2MB, n:5,819.4MB

U-main: 86.0MB

Standard Preview Size: 5120 pixels
Displays: 1) 5120x2880

Graphics Processor Info:
Metal: Apple M4
Init State: GPU for Export supported by default
User Preference: GPU for Export enabled
Enable HDR in Library: OFF

Application folder: /Applications/Adobe Lightroom Classic
Library Path: /Users/aedanpetty/Pictures/Lightroom/Lightroom Catalog.lrcat
Settings Folder: /Users/aedanpetty/Library/Application Support/Adobe/Lightroom

Installed Plugins:
1) AdobeStock
2) Aperture/iPhoto Importer Plug-in
3) Flickr

Config.lua flags: