The colors are red, orange, yellow, green, blue, indigo, violet. You can remember it with the mnemonic device Roy G. Biv made from the first letter of the colors.
The color order is always the same, but each rainbow is different. You may not see all the colors and in some cases the bands of colors could be different sizes. It all depends on how the light is bent. One color could have a much wider band than the others.