Need help building an rgb led music sync.? Answered

I see a lot of step by steps showing how to build a simple vu meter but I am looking to do something a little different. 

I am currently building a new desk and along the back side of the desk I want to install a row of rgb led's.  I would like to set them up so that the led's change color from green to red in increments based on the volume level associated to a certian frequency.  so the far left of the desk responds to low frequency and the far right would be high.

I think this would be pretty cool effect but need some help connecting the dots.  I am hoping there may be some adruino programing availibe to do the signal proccesing and then for each signal I would just need individual volume meters?

the only other thing missing is where to incorporate the rgb settings.