Why would veganism be a yellow flag?
Veganism is caring for the well being of animals.. Veganism is definitely a green flag. Being insufferable is a red flag.
It seems to me you are the one being insufferable. Just because you are not vegan and like eating aninals, you see those who do otherwise as insufferable and self righteous picks and even see veganism as a yellow flag.
PS. I am not vegan.
Are they not the same? Regardless, answer both!