Highway Code - Traffic lights signal

Highway Code UK - Traffic signals
In most cases, in addition to the primary signals at the stop line,there are duplicate signals, known as secondary signals, locatedon the opposite side of the junction. If the primary signal is notworking, you must obey the secondary signal as if it were the primary signal.
1. RED means STOP. Wait behind the stop line on the carriageway until GREEN shows
2. RED and AMBER also means STOP. Do not pass the stop line until GREEN shows
3. GREEN means go IF THE WAY IS CLEAR. Take extra care if you intend to turn left or right, and give way to pedestrians who are crossing
4. AMBER means STOP. You may go on only if the amber appears after you have crossed the stop line or are so close to it that to pull up might cause an accident