Don't buy! The so-called guava-apples in the bright red and green colors sold at RM10 (USD2.9) per pair in Malaysia's Penang State may pose the potential health threat to your health. The artificial colouring was used to fool the people into thinking that the guavas were jumbo-apple hybrids. It is learned olouring agents brilliant blue and tartrazine were mixed for the light-green effect while carmoisine was used for red colouring. linkTags: