Not sure why you want it like this (too much colours, imho).
Besides, Ref Lines cannot be conditionally formatted.
Using "regular" Marks with labels instead.
Please find the attached.
Hope it could help.
Thank you Yuri for your time
I need it like that because they ask to modify a report already built, I just simplified the case with Superstore data. another question here: is there a way to automate pages numbering in Tableau Workbook ??
Not sure I understand your last question.
Could you please post a sample workbook?