Animate background color's saturation or lightness using JQuery

I did a search, and I found a function that randomly changes RGB values only, namely http://buildinternet.com/2009/09/its-a-rainb开发者_StackOverflow中文版ow-color-changing-text-and-backgrounds/

However, I simply want to change a header color's HSL value (either saturation or lightness). I want the color's saturation or lightness to change very slowly and subtly.

Any hints or advice would be appreciated. Thanks.