Some photos...not from Chrono 24 but my own workbench...
These are all photos of the most recent of this model that I serviced a few years ago, so how the watch is lit and how the photos are post processed can have a huge impact on what the dial looks like. Dials fade, so it's not uncommon to see variation just from that. And again there is likely variation if they switched dial suppliers at some point.* All this can give the impression that the dials are different dials, but they are not in this case. This model has never had the actual dial part number change.
* I wasn't doing it at the time of the service of this specific watch, but because of dial variations I now take photos of the back of every dial I remove, to see if there are any noticeable changes in the dial suppliers Omega has been using that affect the look of the watch.
Cheers, Al