My pet theory is that OpenAI screwed up the image normalization calculation and was stuck with the mistake since that's something that can't be worked around.
At the least, it's not present in these new images.
There's still something off in the grading, and I suspect they worked around it
(although I get what you mean, not easily since you already trained)
I'm guessing when they get a clean slate we'll have Image 2 instead of 1.5. In LMArena it was immediately apparent it was an OpenAI model based on visuals.
There's a possibility that any automatic correction could have false positives (since the yellow tint doesn't happen 100% of the time) which creates different problems where a image could have an even weirder hue.
Yeah, though I can imagine a conversation like this:
SWE: "Seriously? import PIL \ read file \ == (c + 10%, m = m, y = y, k = k) \ save file done!"
Exec: "Yeah, and first blogger get's a hold of image #1 they generate, starts saying 'Hey! This thing's been color corrected w/o AI! lol lame'"
Or not, no idea. i've not understood the choice either, besides very intelligent AI-driven auto-touch up for lighting/color correction has been a thing for a while. It's just, for those I end up finding an answer for, maybe 25% of head scratcher decisions do end of having a reasonable, if non intuitive answer for. Here? haven't been able to figure one yet though, or find a reason/mention by someone who appears to have an inside line on it.
At the least, it's not present in these new images.