[pindab0ter]

That makes sense! I can see why you would prefer that skin. Out of curiosity, why use a plugin and not Wikipedia's appearance preferences[1]?

1: https://en.wikipedia.org/wiki/Special:Preferences#mw-prefsec...

[tremon]

IIRC that requires having an account and being logged in, or maybe it just required a persistent cookie to remember the preference. Either way, my browser still aggressively clears cookies on exit so this solution was more permanent for me than the official solution.