Using a small paintbrush, apply a thin layer of yellow, orange, and green decorating batter to two full sheet pan-size silicone baking mats by blotting the bristles onto the mat in a sponge-like manner. Freeze the painted mats for 30 minutes.
Divide the Joconde sponge batter evenly between the painted mats, spreading it quickly, before the decorating batter mel