Wow! Those are some shiny fruits! Quite a few shiny, colorful things actually lack pigments and their apparent color is due to iridescence, the way then bend and reflect light. Supposedly these fruits (Pollia condenstata) are the shiniest of all such biological materials. Now of course plants make attractive fruits to lure seed dispersers, in this case most likely birds, and the birds seek such displays to get a nutritive reward and everyone goes away happy. However these really, really attractive fruits are deceptive providing no reward at all, so any bird that eats these fruits disperses the seeds and considering some effort was involved bascially gets cheated. This works because such fruits mimic a similar rewarding plant, in this case possibly a species of Psychotria (right) that has bright blue rewarding fruits. You don't get fruits colored like this in the temperate zone.