I have a set of hex values in an array in PHP. On my page, I have a slider which the user can "slide" to return a value between 1-100. I want to then, based on this slider value, swap all the colors in the array based on the colors "next" color based on the position in the array. An example of the same sort of thing would be like in photshop where you can rotate the hue of a layer. I want to do the same thing, in PHP, for a hex value.
Any clues?