'White' relates to truths, because it originates in the light of the sun.
(Odkazy: Apocalypse Revealed 167)
Apocalypse Revealed # 257
257. Sealed with seven seals. This symbolizes the Word completely hidden from angel and man.
It is apparent that to be sealed with a seal means, symbolically, to be hidden. Therefore to be sealed with seven seals means, symbolically, to be completely hidden, for seven symbolizes all (no. 10), thus also completely. That the Word was completely hidden from angel and man is soon declared in the following words, "And no one in heaven or on the earth or under the earth was able to open the book and read it, or to look in it" (verses 3, 4). Such is the Word to all to whom the Lamb, or Lord, does not open it.
Because the subject here is the exploration of all people before the Last Judgment, it is the states of life of all in general and in particular that are completely hidden.
Revelation 5
1
I saw, in the right hand of him who sat on the throne, a book written inside and outside, sealed shut with seven seals.
2
I saw a mighty angel proclaiming with a loud voice, "Who is worthy to open the book, and to break its seals?"
3
No one in heaven above, or on the earth, or under the earth, was able to open the book, or to look in it.
4
And I wept much, because no one was found worthy to open the book, or to look in it.
5
One of the elders said to me, "Don't weep. Behold, the Lion who is of the tribe of Judah, the Root of David, has overcome; he who opens the book and its seven seals."
6
I saw in the midst of the throne and of the four living creatures, and in the midst of the elders, a Lamb standing, as though it had been slain, having seven horns, and seven eyes, which are the seven Spirits of God, sent out into all the earth.
7
Then he came, and he took it out of the right hand of him who sat on the throne.
8
Now when he had taken the book, the four living creatures and the twenty-four elders fell down before the Lamb, each one having a harp, and golden bowls full of incense, which are the prayers of the saints.
9
They sang a new song, saying, "You are worthy to take the book, and to open its seals: for you were killed, and bought us for God with your blood, out of every tribe, language, people, and nation,
10
and made us kings and priests to our God, and we will reign on earth."
11
I saw, and I heard something like a voice of many angels around the throne, the living creatures, and the elders; and the number of them was ten thousands of ten thousands, and thousands of thousands;
12
saying with a loud voice, "Worthy is the Lamb who has been killed to receive the power, wealth, wisdom, strength, honor, glory, and blessing!"
13
I heard every created thing which is in heaven, on the earth, under the earth, on the sea, and everything in them, saying, "To him who sits on the throne, and to the Lamb be the blessing, the honor, the glory, and the dominion, forever and ever! Amen!"
14
The four living creatures said, "Amen!" The elders fell down and worshiped.
