'Scarlet,' as in Genesis 38:28, signifies spiritual good.

In Isaiah 1:18, this signifies truth derived from good, or truth from a celestial origin, such as is the truth of the Word in its literal and natural sense

'Scarlet,' in Revelation 17:3, signifies truth from a heavenly origin, such as is the truth of the Word in the sense of the letter or natural sense, which is meant by what is holy in it. 

(Odkazy: Apocalypse Explained 67)

1521. CHAPTER 13

THE LIGHT IN WHICH ANGELS ARE LIVING

Many experiences have made it quite clear to me that spirits and angels possess all of the senses except taste, and that these are far keener and more perfect than man's ever are. Not only do angels see and form relationships with one another, experiencing as they do so supreme happiness resulting from mutual love; there are also more things which they see in their world than man can ever believe. The world of spirits and the heavens are full of representative phenomena like those seen by the prophets, and so many in number that if a person's sight were opened to behold them just for a few hours he would inevitably be dumbfounded. The light in heaven is such as to be unbelievably superior to the light in the physical world at midday. Yet no light from this world reaches those who are in heaven since they are above or within the sphere where that light shines; instead they have Light from the Lord, who is their Sun. To angels even the midday light of the world is like pitch darkness, and when they are allowed to peer at the light, it is as though they were peering into sheer darkness, as I have been given to know from experience. From this it becomes clear how different the light of heaven is from the light of the world.