Claire thank you for your input. It is so interesting because I have also heard of people wearing jade for their health and that different colours of jade aid with different health / body parts. Also many Chinese believe in yin / yang, heating and cooling properties of jade. I think the darker jade is more yin (cooling) and the lighter coloured jade is yang (warming). Maybe when one wears a particular colour of jade that correlates to a health benefit that they particularly need they feel better....
I try to get as intuned as I can with my jade. I can not say that I notice anything healthwise but I do notice the "attachment" I feel to certain pieces. Also looking at my bangles throughout the day makes me happy