Red: The starting berry. It is the weakest of them all and cannot hurt larger enemies such as grasshoppers.
Blue: Twice as powerful as the red berry.
Green: Same power as the blue berry, but it also homes in on enemies.
Purple: Slightly more powerful than the green berry. It also homes in on enemies.
Gold: Strongest of the berries but only slightly stronger than the purple berry and it does not home in on enemies. The biggest advantage of the gold berry is that enemies do not respawn when you defeat them. If you defeat all enemies in the level with the gold berry, you will earn a medal.