I like the idea of a Behavior Log. Students are responsible for logging in their color change and the reason why. Will be good to have on hand as a reference for parents, administers, etc. From--A Day in the Life of a Classroom Teacher: Classroom Tour
This is a link to print out warning Cards. bring the card back in five minutes and tell what you did wrong and how you will fix it. This gives students time to reflect on their behavior and cool down before discussing it with the teacher.