Using CS6, RIGHT CLICK on your Multi Cam Source Clip(notthe sequence you are editing) and OPEN IN TIME LINE. You will see all your video clips stacked in tracks. Choose which track you want to color by toggling the "eyes" button ON and OFF. Add your effect and correction on the specific track (in this case Camera ) and it will instantly update on your MC sequence, when you get back to it.
No need to nest, add an adjustment layer, or color clip by clip.