Chironia baccifera fruit become very red when ripe, earlier green before yellow. The purpose of this ripeness colour indicator must be for the fruits to be noticed among all the green. Birds eat them and thereafter disperse the seed, a plant-bird arrangement contributing to the survival of the species of both participant parties.
If some birds suffered from red-green colour blindness, a human condition, there might be a belly-ache complication. But who would discern from bird song which might be the suffering singers? And who says green berries cause agony in birds? As far as we know bird world has no feathered doctors. And what more we know, is that birds generally can see red, while insects don't.
Starting in Khoi days or before, people have developed a long list of medicinal uses for C. baccifera plant parts. Eating the berries isn’t one of them, as there is a story concerning sheep: Too much C. baccifera thriving in veld where there is too little else that is palatable, kills sheep. What concerns sheep does not always concern people, but this is better left alone as a grey area.
The plant does contain a bitter substance that features in the manufacturing of certain beverages favoured by humans (Vlok and Schutte-Vlok, 2015; Manning, 2007; Van Wyk and Gericke, 2000; Pooley, 1998; iNaturalist).