To fully understand what is happening, it is useful to recognize where various events occur. The apostle John is in the
Temple of God, because the book with the seals are in God's hand (Rev 5:1), and when
Jesus takes it, the 24 elders surrounding God's throne bowed down to Him (Rev 5:8).
When the fourh seal is broken, a seraph calls out an ashen horse whose rider ominously was named Death. Wherever Death went,
Hades followed, which indicates that many non-Believers will be dying. The ashen horse rider is given the authority to see to
the death of 25% of the world's population by conflict, famine, disease, and wild animals.
This is not the first mention of colored horses and their riders.
What Zechariah describes in his first vision (Zech 1:7-11) as sorrel
colored horses may possibly be the ashen colored horse in John's account here. In Zechariah's vision, the sorrel colored horses
follow a red horse while patrolling the earth and their riders were angels.
In Zechariah's eighth vision (Zech 6:1-8), he sees four chariots, which
are the four spirits of heaven. These four chariots / spirits of heaven are angels (2 Ki 6:15-17;
Ps 68:17; Isa 66:15). Going forth between standing
before God and patrolling the earth, the fourth chariot, being pulled by "strong" dappled horses go forth to the south country.
In this instance the dappled description is more closely related to ashen.
Without much detail, it is difficult to understand Zechariah' prophecies; however, one can gain a better understanding of the
colored horses and their riders who emerge with the breaking of the first four seals, and they all work in concert.