i don't know if this helps, but my OUP (1971) version gives
Queste parole di colore oscuro
vid io scritte al sommo d'una porta
These words I saw inscribed in dark characters over a gateway
Incidentally John D. Sinclair's translation is
ABANDON EVERY HOPE, YE THAT ENTER. The word ogni definitely applies to speranza
Interestingly, bearing in mind last week's Listener sites madness, further on Virgil says to Dante "Noi siam venuti al loco ov'io t'ho detto che tu vedra le genti dolorose c'hanno perduto il ben dell' intelletto" We have come to the place where I told thee thou shouldst see the woeful people who have lost the good of the intellect