The kids have this Autumn Spice tea that is quite orange, and they'd had a tea party with it the night before 4/1, so I got some orange Jello at the grocery for a little polymer-prank (they've been studying polymers and making goo/slime too).
Easy "recipe" for making finger-Jello with only one small box.
One 3-oz. box Jello (flavor to match your tea or juice)
2/3 cup boiling water
Mix well and pour into tea cups and small tea pot (or juice glasses and small pitcher). Refrigerate overnight, and serve to unsuspecting children in the morning. Trust me, they'll think it's hilarious.