Of the Four Horsemen, the red horse is the easiest to interpret. While war is the predominant symbol, the rider of the red horse may strike closer to home.
Satan is the opponent of God, of believers, and of all that is right and good. He may appear as 'an angel of light', but this is only a façade.
The Hebrews perceived color differently than we do, assigning symbolic significance to a number of different colors as they associate with concrete objects.
Satan was first named Helel, or 'son of the dawn.' When Jerome translated the Hebrew into Latin, he named him Lucifer, or light-bringer, a title of Christ!