The second seal can be found in Revelation 6:3-4 and reads as follows…
“When He opened the second seal, I heard the second living creature saying, ‘Come and see.’ Another horse, fiery red, went out. And it was granted to the one who sat on it to take peace from the earth, and that people should kill one another; and there was given to him a great sword.”
>> The 7 seals: background & overview
>> The 3rd seal and the black horse
>> The first seal and the white horse
Red is an appropriate color for this period up to the days of the emperor Constantine, who was the first world ruler to profess the Christian faith.
During this time of pagan persecution the Roman emperors attempted to stamp Christianity from the face of the earth. The amphitheaters and arenas witnessed the death of thousands of the martyrs of Jesus. Sometimes ferocious lions and other beasts would be starved for days and then suddenly turned loose to tear in pieces a band of Christians, old and young.
Those who professed the name of Christ were sometimes tied to posts, covered with pitch, and lighted as torches to illuminate the festivities in Nero’s gardens.
Whenever any great natural calamity occurred it was blamed on the Christians, and the fury of the mobs was vented upon them. Many Christians fled to the catacombs of Rome and lived and worshiped in those gloomy underground passageways.
Bloody persecution did not stamp out the blessed hope of the gospel. It just spread the faith all over the world. It has been said that the blood of the martyrs was the seed of the early church.