I bought the perfect pitch/relative pitch supercourse years ago before it came out on cd... The perfect pitch portion requires a partner to play notes for you while you try and identify their character. I didn't get very far with it, however, I did in fact hear the pitch color quality that he refers to. For most people, it will take at minimum one to two years to be able to identify pitch color of any instrument at any time.
I completed the relative pitch portion of the course (where you will learn about chords and their variants), and you begin to appreciate the benefits much sooner. It is also about the best introduction to music theory you will ever find, because you aren't reading about it, but memorizing how relationships of pitches sound and building your knowledge solely based on what your ear can pick up. You will also have a much more sensitive ear to tuning, and you will be able to take music out of your head and put it down on paper (he doesn't teach you how to read music, and you don't need to know how to read music to take the course. You would simply write down the notes you hear in your head).
I highly recommend it, however, it is quite time consuming. One of these days when I have some cash to blow I may get the cds and try the perfect pitch again.