No more school lunch

I cancelled my school lunch at my junior high school because I sit at my desk with no children interaction. I thought it would be okay to bring in my own or buy it from the bakery next door. Yes more pizza with corn and mayo on it. Yuck. I went to the microwave to heat up my food. I pushed a few. Beep, beep-beep. Nope, try again. Beep, beep, beep. Maybe a different combo. Beep...... beep.. beep. Still no. I turn around to ask the secretary. She had set her chopsticks on her tray with a big smile "need some help?" Ohhh my mistake- red means start not stop. Most countries you want to stay away from red. This time it means hot. Okay I will remember that next time. What is the color to stay away from then? Still got me some learnin to do.