Here is the link to the graph builder legend documentation:
In the fit Y-by-X platform you can right click and select "Row Legend" to color and add a legend to your plot based on a column. When looking for such items 1. red triangle, 2. right click, 3. Google key word + JMP, 4. JMP community. If you still can't find what you are looking for if you can share your data table (Tables > Anonymize) then someone can probably help you quickly.
Karen