Well shit. I thought this was a joke comment, but TIL. Cool thanks!

The ‘Rio Red’ is a mutation-bred variety that was developed by treatment of bud sticks with thermal neutrons. Its improved attributes of mutant variety are fruit and juice color, deeper red, and wide adaptation.

This is one of two grapefruit I have growing in my yard and my favorite variety.

but what is sold as grapefruit juice is actually a bison blood mixed with tangerine.