There is no one, official Protestant interpretation. However, I can give information from a book compiled by a Protestant scholar but which makes no distinction between basically Catholic, and basically Protestant stances. He offers an even-handed summary of the four traditional views of Revelation in parallel columns, allowing the reader to compare each view quickly and easily. The four main views are:
Preterist – most prophecies were fulfilled during the time of the Roman empire.
Historicist: the prophecies have been fulfilled throughout history and are still being fulfilled today.
Futurist: most prophecies are yet to be fulfilled.
Spiritual (or Symbolic or Idealist): most prophecies portray ongoing cosmic conflict of spiritual realities and may have many fulfilments throughout history.
Revelation 6:2-8 equates the breaking open of four seals with the appearing of the four horsemen; a rider on a white horse, a rider on a red horse, a rider on a black horse and a rider on (either) a pale or a sickly green horse.
The Historicist view says the white horse represents the period of five good Roman emperors from Nerva to Marcus Aurelius. The second seal was from the accession of Commodus to Diocletian. The third seal is viewed as the fiscal oppression imposed by some of the emperors of the third century (or a later period). The fourth seal was from A.D. 248 to 268 or 296.
The Preterist view says the seven seals are on a row on the overlapping lip of the document, making it impossible to begin opening the scroll until all seven seals are removed. In this view, nothing happens historically until the seventh seal is broken in Revelation 8:1. Others believe it gives a progression of events leading to the destruction of Jerusalem in A.D. 70.
The Futurists see the Tribulation beginning with the breaking of the first seal. Some see the rider of the white horse being the Antichrist. The red horse represents the bloodshed of Tribulation war with the black horse being the famine following, and the fourth horse being global death and hellish destruction.
The Spiritual/Symbolic view can include Christ as being the rider on the white horse, the four riders representing the universal sequence of conquest, war, famine and death, this proceeding from God’s sovereign purpose in judging a corrupt humanity. Some see this also (in addition) in John’s day, the time of Domitian.
I cannot begin to do justice to the many views about the four horsemen, so would recommend you get this book – Revelation – Four Views edited by Steve Gregg, published by Thomas Nelson Inc. in 1997. He names leading theologians in connection with the various views, so that would give you a guide as to particular denominations.