Red, Orange, Yellow, Green, Blue, Indigo and Violet!
Here's an image of the colors of the rainbow in order which makes it easy for you to see how they work in order. Enjoy!
The order of the rainbow is ROYGBIV (red, orange, yellow, green, blue, indigo, and violet). It is caused by a breakup of white light wavelength (all colors) when it hits water. It is refracted as it passes through the water droplets in the sky (moisture after rain) and breaks into 7 different sizes of wavelengths. The largest of the color wavelength is Red and the smallest is Violet. They have the different sizes due to the amount of energy they come with as they travel from the sun to our eyes!
Violet, Indigo, Blue, Green, Yellow, Orange, Red.
You must remember though that red is the longest wavelength in the visible spectrum and appears at the top of rainbows and to the left-hand side on a horizontal wavelength spectrum while violet is the shortest wavelength in the visible spectrum and appears on the bottom of rainbows and to the right-hand side on a horizontal wavelength spectrum. So, reading left to right, the order of the colors is red, orange, yellow, green, blue, indigo and violet:
These are the seven colours on the visible spectrum. Beyond violet are the ultraviolet rays and before red are the infrared rays.
The Colors in the rainbow order are easy to remember with ROY G. BIV
Isaac Newton, to whom we owe a great deal of gratitude for his pioneering work on what light is and how colors combine to make the rainbow, summarized it as you have seen in other answers to this questions: Red -- Orange -- Yellow -- Green -- Blue -- Indigo -- and Violet. However this can be a little misleading for two reasons.
1. There are actually many more colors in the rainbow than we have names for. Our eyes are capable of distinguishing millions of individual shades of color!
2. When we think about the rainbow in the ROYGBIV colors, we usually make a mistake. What many people call "blue" in the rainbow is actually cyan, you know, like what you use in your color printer. Cyan stimulates the parts of our eye that see green and blue equally. Your computer monitor that you are looking at right now produces cyan by combining equal light levels of green and blue as well. The actual pure blue, is what Newton unfortunately referred to as "indigo." So in terms of what colors are actually there, a more accurate summary of the rainbow would be Red -- Orange -- Yellow -- Green -- Cyan -- Blue -- Violet
A rainbow is made by the reflection and refraction of light that interacts with raindrops. Depending on how this interaction occurs with your location relative to the sun and the raindrops you may see a primary and even a secondary rainbow.
The interaction that occurs to create the primary rainbow will produce a spectrum of colors in order Red - Orange - Yellow - Green - Blue - Indigo -Violet (ROY G BIV) with Red occuring on the outside edge of the rainbow to Violet occuring on the insdie edge (closest to the center) of the rainbow.
The extra reflection that occurs to produce the secondary rainbow causes the colors to reverse order. So on the secondary rainbow Red will occur on the inside edge followed by Orange, Yellow, Green, Blue, Indigo, then Violet on the outside edge of the secondary rainbow.
Check the sites below if you want to see a little more detail on how this works.
Always remember, ROY G BIV.
When you see a rainbow, it is actually part of the electromagnetic spectrum known as visible light. This part of the spectrum can be detected by the human eye and falls between 390-750nm in terms of wavelength. When sunlight passes through water droplets in the atmosphere, they can act like a prism and separate the white light into the colors of the rainbow. These colors are red, orange, yellow, green, blue, indigo and violet. Red waves are longer and violet are shorter. You will see the color red on the outside arc of the rainbow and the violet on the inside arc. You can remember the visible spectrum by memorizing the name ROY. G. BIV. Each letter in the name corresponds to the colors of the rainbow. R stands for red, O for orange, Y for yellow and so on.