Each ring was designated a color, which follow a set order: blue, black, yellow, green and red, placed in two rows on a white ...

Lightning comes in every color of the rainbow (Red, Yellow, Green, Cyan, Blue, and Violet, to name a few). It's almost always white, but often it's tinged with another color around the edges.

You can use a prism to split (or disperse) white light into a spectrum of colours: red, orange, yellow, green, blue, indigo and violet. Dispersed means that the colours are separated out.