The red/green difference view is a UI feature of the prompt editor that shows when the system detects a proposed change awaiting your review — it’s controlled by the Studio Web frontend.
This functionality has not been working for the last couple of days. I reported it in feedback and am just raising it here.
That feature was quite useful for controlling how the auto-pilot makes limited changes to the prompt. Without this highlight, the user would have to manually compare the texts to find out which parts of the prompt the auto-pilot fixed.
