From Zelda Legends Wiki
Spoils from defeated ChuChus, these little globs of jelly can be taken to Doc Bandam at Windfall Island and turned into their respective potions. With 15 Chu Jelly of a single color, Bandam can create a new potion type of that color, and can make another potion of the same color for five Chu Jellies afterwards.
Red Chu Jelly
Red Chu Jelly comes from Red ChuChus and is used to make Red Potions.
Green Chu Jelly
Green Chu Jelly comes from Green ChuChus and is used to make Green Potions.
Blue Chu Jelly
Blue Chu Jelly comes from Blue ChuChus and is used to make Blue Potions.