Once a script is in production, the office tracks changes by colored pages in a fixed order, starting from the White shooting draft. Revision mode marks every changed line with an asterisk in the margin and keeps page numbers stable so the crew's binders stay right. Pro and above
Make a save point of the shooting draft
Before locking, press CtrlShiftS and name it ("White — shooting draft"). Everything after this is measured against it.
Lock the production draft
Open the History tab. Its revision panel says the script is not in production yet; choose Lock production draft. The save point becomes the White shooting draft, page numbering locks — new material becomes A-pages rather than shifting what follows — and Blue, the first color in the sequence, starts.
The revision panel in the History tab once the draft is locked: the current revision and its color (1), each scene's revised status (2), and Lock Blue pages (3), which issues the Blue revision and starts the next color. Make the changes
Write as usual. Every line you touch gets an asterisk in the margin, and the panel's scene list shows which scenes carry revisions.
Lock the pages
Choose Lock Blue pages. Plot asks you to confirm, makes a save point named for the color, and starts the next color in the office's order. A PDF exported now carries the revision marks and the color — see Export PDF, FDX, and Fountain.