The fourth and final horseman is named Death. Known as "the pale rider; of all the riders, he is the only one to whom the text itself explicitly gives a name. Unlike the other three, he is not described carrying a weapon or other object, instead he is followed by Hades. However, illustrations commonly depict him carrying a scythe (like the Grim Reaper), sword, or other implement.
The color of Death's horse is written as khlōros in the original Koine Greek, which can mean either green/greenish-yellow or pale/pallid, hence, The Pale Horse. The color is often translated as "pale", though "ashen", "pale green", and "yellowish green are other possible interpretations (the Greek word is the root of "chlorophyll" and "chlorine"). Based on uses of the word in ancient Greek medical literature, several scholars suggest that the color reflects the sickly pallor of a corpse. In some modern artistic depictions, the horse is distinctly green.
The verse beginning "they were given power over a fourth of the earth" is generally taken as referring to Death and Hades, although some commentators see it as applying to all four horsemen. In either case, it's a good bet you won't survive this tragic period anyway.