How to visually format questions/answers in an easy to follow the story?

I'm designing a booklet about science facts and stories for kids. The format of the content is based on questions and answers between a teacher and a student. It's text based, few images/graphics are used. The booklet tries to emulate a real interaction between a student that wants to learn more about science and the teacher. My question is how to visually format all those questions/answers in an easy to follow the story?

Things that I want to avoid.

• Enclose the spoken words with quotation marks. The whole booklet is a "dialog", so it will look quite ugly having every sentence/paragraph quoted.

• Using an indicator like A: and Q:. That can help separate the questions from the answers, but it doesn't indicate who is "talking", if is the teacher or the student.

I initially thought in separate the content by colours. For example. When the teacher "talk", the font or background would be in blue. The student will be yellow. My concern is that a) it will increase the printing price b) it may become "too" colourful. So, I'm not sure now.