Visually both designs are beautiful. About its connection to personality: I personally always go with the "mysterious/dark" look because that's how foxes are and those who relate their personality with a fox are "stealth" people but I don't know you very much XDDD and since she is your fursona well.. you know yourself xd. Maybe you could do a combination of both design to give her a charismatic and stealthy looks?
I agree with HereLiesDeadSquirrel. Try not to stress out too much over her final design. My own fursona's design changes often enough. Don't feel you have to settle on a single design if you're still unsure right now; continue experimenting.
Perhaps a combination of the two? Or perhaps whichever season is your least favorite would be when she acquires the "dark" coat and your favorite season would be for the "happy" coat (EX: Winter is your least favorite so the "dark" coat would be her Winter coat.)