At the moment when you look at the main page of questions there are 3 different categories of questions differentiated by colour:
Questions with no answers:
Questions with answers but none accepted:
**Question with accepted answer:
**
I think it would be useful for there to be a difference between "questions that have answers but no upvoted answers" and "questions that have upvoted answers". I think it would encourage people to look at questions with no upvoted answers, which they may normally ignore looking at as it would seem there is already an answer. It may also encourage to look and vote on new answers.
As a note, the mobile version of the site already has this functionality, with the font colour different dependent on whether a question has answers with upvotes:
Answers but no upvotes
Answers with upvotes
Question has accepted answer