Revelation 4:3

4:3 And the one seated on it was like jasper and carnelian in appearance, and a rainbow looking like it was made of emerald encircled the throne.

Revelation 10:1

The Angel with the Little Scroll

10:1 Then I saw another powerful angel descending from heaven, wrapped in a cloud, with a rainbow above his head; his face was like the sun and his legs were like pillars of fire.