It is appealing to equate these horses with those mentioned in Revelation 9:7–11 and so conclude that they represent demons. The problem with that equation is that Revelation 9:7–11 are not about horses but about locusts, who look like horses. Instead, the horses of the sixth trumpet appear when the four angels at the borders of heathendom were released from their bondage to invade the land given to the descendants of Abraham.
17 Et ainsi dans la vision je vis les chevaux et ceux qui les montaient, ayant des cuirasses couleur de feu, d'hyacinthe, et de soufre. Les têtes des chevaux étaient comme des têtes de lions; et de leur bouche il sortait du feu, de la fumée, et du soufre.