I contain many letters, countless in fact, yet my name consists of only two words, for a total of ten letters. What am I?

I was named for my color - take my first four letters and you'll see. Yet in my full form, I'm a product of deadly chemistry.

I can make the first move, but I cannot lead the way. People use me to part with their own.

My first half makes you grimace at first bite, my second shines bright in the dead of night. Together, I am an actor's favorite sight.

I am hoarded in panic, yet I vanish in haste, I stick by your side, in your darkest hour. I ease your toil when nature won’t wait, Then I let you leave in a fresher state.