Pink grapefruit does not have the enzyme in it that interacts with drugs metabolized by CYP3A4.
ALL types of grapefruit have the potential to interact with drugs metabolized by CYP3A4.
Enzyme levels may vary among different types of grapefruit...which in turn affects the grapefruit's capacity to inhibit CYP3A4. Enzymes may also vary depending on where and when the grapefruit was harvested, whether it's consumed whole, or as fresh or frozen juice.
Different brands and lots of grapefruit juice even contain different concentrations of enzymes...and may cause a different level of interaction.