Blue light vs white light

Recently I've read that research in 2010 has shown blue light to be LESS effective for SAD than green or traditional white light. This contradicts what I read a couple of years ago, which led to me buying a blue light Apollo GoLite M2. Now I'm wondering if this is why it is not as effective at relieving depression as I had expected (although it is very good at getting me up and going and regulating sleep; my motherinlaw says its brilliant for jetlag).

I'm thinking of getting a second lightbox, maybe a strong white light one (does anyone even make a green light one?), but I'd welcome your experiences and comments on blue vs green vs white light for relieving the depressive symptoms of SAD, and any product recommendations, ie are larger boxes more effective than portable ones.
Thanks!
Helen