Peace of mind at a glance the innovative gro egg changes colour to let you know at a glance whether the temperature of a room is too low too high or just right helping you maintain a safe sleeping environment for your baby as an added bonus it even works well as a gentle night light a yellow glow suggests a comfortable temperature for children to sleep in whilst a blue glow suggests its too cold and a red glow suggests its too warm the colours act as a reminder for you to cool or heat