Why so many fruits/veg fall into these color categories?

Disclaimer: This question is not about cooking per se, rather about food itself; please let me know if this is not appropriate for this SE.

I have noticed that there are many fruits and vegetables which seem unrelated that come in two color varieties, red and yellowish-green. What I mean by this is that we have red onions and yellowish-green onions, we have red apples and yellowish-green apples. I will put a list of all such foods I have thought of; but I can’t seem to find a reason why? Does this have to do with the chemistry, or the environmental conditions that cause different varieties to have different colors. I’ve tried looking online for this, but I cannot seem to formalize my question in a succinct and clear way to obtain results.

Here is a list of fruits and vegetables which have red varieties and yellowish-green varietes.

• Apples
• Onions
• Raddish
• Bell Peppers
• Potatoes
• Figs
• Dragon Fruit (Yellow Dragon fruit are called Kirin)
• Peaches (Green Peaches are common in the middle-east)
• There are a few more which I cannot remember; I will add in edits.

I am of course open to the possibility that this is all random correlation and for every instance I’ve found here there are more instances in some other arbitrary pattern. But there seems to be something happening here.