The teacher is implementing a new behavior system in the classroom using a color-coded system to track student behavior throughout the day. Students will start each day on green, and can move their color up to purple for good behavior or down to red for poor behavior choices. At the end of the day, the teacher will send home notes for any students on yellow, orange or red to inform parents of their child's behavior. The system aims to make students more accountable for their actions and choices in school.