Genesis 9:13 (a) Our Lord gives this emblem as a proof of His grace and mercy. It is a sign of the immutability of His Word. Now we never see a complete rainbow. It is always broken at the bottom, and there is a space there where there is no color. So none of us ever see all the grace of GOD for our lives, all His goodness and mercy, and all the perfect plan He has for us.
Revelation 4:3 (a) The bow in this Scripture is a complete one. There is no break in it. All the colors have disappeared, except the green. Green is the color that represents praise and worship. The complete bow tells us that in the next life we shall see and understand all the goodness of GOD to us, all His grace in dealing with us, all His measureless mercy which preserved us. Because of this we shall spend eternity in adoring praise and worship.
Revelation 10:1 (a) Since the rainbow appears around the head of this mighty angel just before the judgments begin, it is to tell us that grace always appears before wrath, and GOD's goodness provides a remedy from the dire results of rebellion.