Vicious Desire definitely seems Watermelon flavored.



Juicy Sunshine would probably be very citrus-y, maybe something like orange, or sweet lemon?



Magical Mystery could be anything, or even change from lollipop to lollipop.



Moonshine BLues would have to be some sort of blue flavor, like raspberry, blueberry, or something like that.



Awesome Performance, I would guess Cotton Candy flavored.



Sweet candy looks like it's probably a mix, just like Cadence's mane. Grape, berry, and lemon?