One last character to go! Glitch in game?

My kid has 1 character left...Carlo Cone. We've changed the balloons from grey to yellow and red...all of them are red and yellow yet no Carlo Cone. We've tried everything but nothing works. When we turn off the game and then go back to the balloons at Crescent Park there is one grey balloon that we then hit Witt he multi color gun and it turns it yellow, making all balloons alternating yellow and red. Still nothing. Any thoughts?