how many colours are in a rainbow
You can remember them because they spell out ROY G BIV. The first letter of the colors red, orange, yellow, green, blue, violet and indigo. Rainbows are commonly thought as having 7 colors. The colors in order are: 1  Red. 2  Orange. 3  Yellow. 4  Green. 5  Blue. 6  Indigo. 7  Violet.