But this is exactly what you expect when you ask intelligence (machine or human) to fill in missing information. It picks some plausible, middle-of-the-road filler. If you were a restoration artist with an airbrush (or photoshop) with just the instruction to make the picture nicer, that's what you'd do. If you got told the right colour, you use it, and if not, you guess.
I bet that ChatGPT actually would regurgitate exactly this notion but cannot effectuate it.