Even though they’re mostly anecdotic, there seems to be a consensus that both are used. There are some articles stating they’re 9 and others stating they’re 7, and depending who you ask they’ll tell you one or another.

Un chat usagé a sept vies, mais un chat neuf vies

• https://hinative.com/questions/12217466
• https://www.reddit.com/r/linguisticshumor/comments/1cdz8kz/comment/l1fcop3/
• https://jardinage.lemonde.fr/dossier-1795-vies-chat-histoire-legende.html
• https://umvie.com/origine-et-signification-pourquoi-dit-on-quun-chat-a-7-vies/

Its explained in the post. It’s for daltonic people to be able to see it bettee, although I dont have experience with it so I don’t know if I did it right

Wow, a blast from the past! I love Pinkie’s Brew in russian!