Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
Q&A for work
Connect and share knowledge within a single location that is structured and easy to search.
I read the whole FAQ and I did not find that answer.
I think you are talking about the dotted line? Red means there are no answers. Light green means the question has been answered, and dark green means an answer has been accepted.