SALVATION : The word translated “salvation” here (1 Peter 1, see below) is Strong’s Greek # 4991: “Deliverance, preservation, safety, salvation: deliverance from the molestation of enemies, Acts 7:25; with ἐξ ἐχθρῶν added, Luke 1:71; preservation (of physical life), safety, Acts 27:34; Hebrews 11:7. (Biblehub)

RAINBOW : “A rainbow, resembling an emerald, encircled the throne…” Revelation 4:3b

“Ultimately, our infinite God accomplished His PERFECT will in everything He created, right into infinity. You can find the number 7 intelligently designed into many things (including the seven wavelengths of the electromagnetic spectrum, the colors of the Rainbow), and it’s referenced numerous times in the Bible. One such reference are the Seven spirits of God, as found in the prophecies about Jesus in the book of Isaiah:
“And the [1] Spirit of the LORD shall rest upon him (Jesus), the [2] Spirit of wisdom and [3] understanding, the [4] Spirit of counsel and [5] might, the [6] Spirit of knowledge and the [7] fear of the LORD. (Isaiah 11:2)”

There are many studies on the parallels between the SEVEN SPIRITS OF GOD and the seven colors of the visible light spectrum.

“The one other very obvious observation is that the three primary colors (red, green, blue) are responsible for creating the secondary colors. This is in direct parallel to the work of the Father, the Son (Jesus), and the Holy Spirit.” (Glimpse of Infinity)

SCIENCE : Light can trigger coordinated, WAVELIKE motions of atoms in atom-thin layers of CRYSTAL, scientists have shown. A WAVE on the surface of water is the closest analogy,” said Dimitri Basov, professor of physics at the University of California, San Diego, who led the project. “You throw a stone and you launch concentric WAVES that move outward. Atoms are moving. The triggering event is ILLUMINATION WITH LIGHT.” (UCSD,edu)

“At once I was in the Spirit, and behold, a throne stood in heaven, with One seated on the throne. And He who sat there had the appearance of jasper and carnelian, and around the throne was a RAINBOW that had the appearance of an emerald. Around the throne were twenty-four thrones, and seated on the thrones were twenty-four elders, clothed in white garments, with golden crowns on their heads. From the throne came flashes of lightning, and rumblings and peals of thunder, and before the throne were burning seven torches of fire, which are the SEVEN SPIRITS OF GOD, and before the throne there was as it were a SEA OF GLASS, LIKE CRYSTAL.” Revelation 4:2-6

“I beheld till the thrones were cast down, and the Ancient of days did sit, Whose garment was white as snow, and the hair of His head like the pure wool: His throne was like the fiery flame, and His wheels as burning fire. A RIVER OF FIRE was flowing, streaming out from His presence. Thousands upon thousands attended Him, and myriads upon myriads stood before Him. The court was convened, and the books were opened.” Daniel 7:9-10

“Then the angel showed me a RIVER OF THE WATER OF LIFE, as clear as CRYSTAL, (Diffusing the Light into the spectrum of the Rainbow) flowing from the throne of God and of the Lamb.” Revelation 22:1

“You, who are being GUARDED by the power of God through FAITH, for the SALVATION (see above) ready to be revealed in the last time, in which you greatly rejoice, at present for a little while if it is being necessary, having been put to grief by various trials, so that the proven genuineness of your faith, more precious than gold, perishing though being refined by fire, may be discovered to result in praise and glory and honor in the revelation of Jesus Christ, whom not having seen you love, on whom now believing though not seeing you also exult with JOY inexpressible and filled with GLORY, receiving the outcome of your faith, the salvation of your souls.” 1 Peter 1:5-9

“Concerning this SALVATION (see above) the prophets sought out and searched out diligently, having prophesied of the GRACE toward you, inquiring into what or what manner of time the Spirit of Christ in them was signifying, testifying beforehand of the sufferings of Christ and the GLORIES after these, to whom it was revealed that they were serving not themselves, but you, in those things which now have been proclaimed to you by those having proclaimed the gospel to you by the HOLY SPIRIT having been sent from heaven, into which angels desire to look.” (The prophets LONGED to see these times, because of the GLORY poured out upon us and in us, so much so that even the angels LONG to see it and be a part of it)” 1 Peter 1:10-12

“Deep calls unto deep at the noise of Your waterfalls; all Your WAVES and billows have gone over me. The LORD will command His loving kindness in the daytime, and in the night His song shall be with me — A prayer to the God of my life.” Psalm 42:7-8

“From His FULLNESS we have all received GRACE UPON GRACE. For the law was given through Moses; GRACE and truth came through Jesus Christ.” John 1:16-17