This is a rainbow link.
To make all the links on your website flash rainbow colors, download this file: rainbow.js by right-click, and choosing "save target as". Place the file where you keep the web pages that you want rainbow links on. Open those web pages in notepad, and place this in the <head> section:
That's all there is to it. If you want to speed up or slow down the flash speed, open rainbow.js in notepad, and go here:
var rate = 30; // Increase amount(The degree of the transmutation)
30 equals the speed of the flash. A higher number means a faster change rate.