Here are the colors of the smiley faces and what each color means:
I have a sheet that I put in the students homework folders every night. I color what face they got for the day and check mark underneath the rule/rules that were broken. The parents have to initial this sheet every night. I am attaching a copy of my Weekly Behavior Report for you to use in your classroom if you wish. This method has worked great for me and I hope that it can help you too.