Why are fruits and vegetables red or green? Are they not all healthy?

We live by the motto "one person's food may be another person's poison."

Everyone is unique, everyone has unique epigenetics and respectively, everyone has different tolerance thresholds regardless of whether or not the food item is deemed "healthy" in societal standards. 

It may be that the particular fruit or vegetable item is just not currently compatible with the current epigenetic state of your body. 

For example, strawberries are also a fruit, however, some people may be allergic to them and the consequences can be fatal. 

If you know you have an allergy or suspect you have an allergy you must contact your medical professional or allergy specialist.