GPT Image 1 ended up with a yellow tint without training on another image-generation model's output. It's just that humans like pictures with a soft sunset glow, and this is a very easy global signal for a preference model to pick up on, and for a image-generation model to imitate. So optimizing for aesthetic appeal makes everything slightly tinted by default, unless you make sure to countersteer.

yellow/red tint is an extremely common problem not matter the photograph source you train on

source: work at a photograph start, even training on raw images things get tinted, it is an uphill battle

Maybe it was trained in a Mexican data center https://en.wikipedia.org/wiki/Mexican_filter

AI-generated images are part of the web now, if you're doing ordinary web scraping, you can't avoid training on generated images.

You clearly haven't met a Chinese RedNote user.