Poinsettias require short days and long nights in order to bloom and for their bracts to turn color. They need total blackness if possible; you don't even want the light from the moon or stars to...
Its rare. But only if you're in the left hand lane of a one-way road at a stop light, and you're turning left onto another one-way road.
You use hair dye.
the oxygen
If you soak a flower in red dye it will turns the vains inside the stem and leaves red.