Dating a collegue is not bad, but cannot be good either. One has to define a little broaderly the term good for himself & should try to achieve it.
You only can fall in Love with a collegue when your world is limited to your office boundary. You might not have experienced the other world yet. So just give yourself another chance before making a decision.
Life is a change & so does it requires change to fulfill it. A collegue with same qualities, same expereince, same dreams can\\\'t bring any change to the already changeless-office life.
It may not hamper productivity. It isn\\\'t aganaist any ethics or morality. But it is not the last resort either. Life is a rainbow only when all the colours mix.