Yellow, then red is the patterns of the traffic lights.
your not so bright
Don't look; I'm changing
Nothing. there is no blue light.
If the traffic light is not powered, you are to treat it as a all-way stop sign. I'm assuming that's what you mean by that. If the traffic light is broken, likely there will be utility workers out there working to fix it and you follow their instructions if any.
A yellow arrow traffic light means that you should yield in the direction you are going. These are often in place when you are turning left.
When the traffic light comes into view and it's green, it was likely green for a long time, unless you also observe cars just starting to get going. If you see the traffic light is green in the distance we call this green light "stale", meaning it could turn yellow any second. A traffic light that just turned green, we call this green light "fresh", meaning it just turned green and it won't be turning yellow for a little while. Of course these times between from when it turns green then back to yellow and red again varies on the intersection. To answer the question when you're approaching a green traffic light you should prepare to stop as that green light is "stale". You don't necessarily have to slow down just get ready to hit the brake.
The green light on the traffic light is on the bottom. The yellow is in middle, the red is on top. However, in some municipalities, the traffic lights are not vertical, they are horizontal. In these instances, the green light is usually, but not always, the furthest to the right.
A traffic light you seen change to green
a fresh green light is when the traffic light has just turned from red to green
It is usually on the bottom of the traffic light.
'Go'.
Yellow light
The lowest light on a traffic signal is green. Some cities use traffic lights that are not arranges top to bottom but rather side to side. In this event the green light is usually the furthest to the right.
On a vertical display traffic signal the green light is on the bottom. On a horizontal display traffic signal it is to the right, but may depend on that state (or municipality's) practice.
Fresh green light
bottom
Depends. If the light has a sign next to it that says 'Yield on green light' it means you can go when the light is green and there is no traffic coming from the opposite direction that could hit you. If there is no sign wait for the arrow.