I am a new owner of a JTV 89F. I am in two bands and bought it mainly for the ease of handling tunes within a set list that require alternate tunings but to some degree the modeled guitars also. I have found the support/user literature to be lacking, in particular the "basics" of how to engage the model options for tunings and guitar. My biggest question is, why do I sometimes get blue light vs. white light on the knobs, and why do they sometimes flash? It almost definitely means SOMETHING, but what?