Just a couple of snippets:

Black foods, beauty foods and amino acids are currently among the most popular products for health-conscious consumers in Asia but none of these have yet been exploited on European soil, said analyst David Jago.

Black foods often include ingredients like black vinegar, black soybeans or black sesame, all with growing reputations for health benefits, especially in Japan. Foods with such a dark colour often contain more anthocyanins, isoflavones and minerals than more lightly coloured foods.

"These really fit into that ying-yang philosophy, and are typically protein-rich, strongly flavoured and suited to winter consumption," added Jago.

One such product proving popular in Japan is an Itoen drink containing 17 kinds of vegetables and 15ml of black vinegar. Another is a black sesame paste available in China for stirring into hot water for a good start to the day.

This is interesting:

There are still more black foods, likeblack rice, black sesame, black sesame tofu, pudding, Nori, Hijiki, sea vegetables, squid ink (Santos, all your dishes are so great!! I am always so impressed). If you do'nt like or can't find black food around you, one good feature of black food is found in other products: Cyanidin is found in red wine, grapes, bilberries, blueberries, black cherries, cocoa powder, and similarly dark-colored foods.

And this:

Black/dark foods come from both plant and animal origins. Foods from plant origin include black rice, black soybean, black sesame, black plum, black mulberry, purple seaweed, kelp, and black mushroom. Foods from animal origin include sea cucumber, black chicken, cuttle fish, grass eel, turtle, black snail, and frog. Studies on proximate composition, dietary fiber, amino acids, minerals and other minor elements show that foods in black color contain higher levels as compared with other colour foods.

Hmmm, I don't know ... it does make sense that there are health benefits to those types of foods I guess?