ummmmmm. . . blue. . .

I have been proven wrong. I googled ''blue raspberry",  and got a wikipedia page that said this:

"Blue raspberry flavor is a common flavoring for candy, snack foods, sweet syrups and soft drinks. The flavor originates from Rubus leucodermis, more commonly known as the "Whitebark Raspberry" or 'Blue Raspberry' for the dark red to blue-black color of its fruit.

Food products labeled as Blue Raspberry flavor often contain a bright blue food coloring (although this coloring is not accurate to the real-life color of the fruit)."