That's exactly what I think of.
I think of layers of different Jello colors and flavours.
I think of whipping some of the layers to put bubbles in it.
I think of whipped cream
I think of using Jello pudding somehow.
I think of adding fruit to Jello( peaches, mandarins, kiwi, strawberries, blueberries) etc.
I have an idea , that you could make Jello shapes, then add them to almost set other Jello molds, in a clear glass trifle bowl and see the shapes floating, through the setting Jello. of course contrasting colors.