Gradient blue jelly

Quick answer：

Gradient blue jelly is a type of jelly made with a blue color that has a gradient effect. It is a sweet dessert that is often found in Chinese cuisine, particularly in the southern regions. The jelly is made by dissolving gelatin in water and adding a blue food coloring that creates a gradual color change from light to dark blue. It is typically served chilled and can be found in various forms, such as in cubes or as a solid block.