Problem with colours on HDR panorama DNG

As mentioned, ACR ignores the settings, so you might try saving the files as a tif then stitching them in ACR.

Thank you for your response, I've had another attempt and tried stitching the panorama using the bracketed shots without the preset and applying the preset after the stitching in ACR, It still produced the same error in the colours.

I managed to find a solution, making note of the settings used in the preset and applying them one by one until I found the dehaze setting was causing the colour shift.

Just seems odd the dehaze works fine when applied to individual frames but completely shifts the colours when applied to a panorama

ACR ignores any settings when it merges images, so the custom preset you applied is ignored. To see if you can find an explanation, you must look at the unedited images. Remember that ACR is not intelligent in any way. It tries to match colors to seamlessly stitch the images, but it doesn't know what it is looking at, so if one image is clearly different in color, ACR may seriously change it trying to match it tomits neighbors.