I have sooo gotta figure this one out. So here goes.
This is the original pic that sparked my curiosity.
Now to figure out how to color the marshmallows.
Here are a couple of ideas I ran across to possible make it happen.
I read it's just like dying an egg without warm water and vinegar solution. Submerge the marshmallow in water wtih drops of food coloring and leave until the desired color is obtained I would think they need to dry for a few hours or maybe even overnight. Also be sure to use cold water as the marshmallow may try to dissolve. I would think toothpicks would keep the tootsies in place.
Idea #2: I found another idea that is at the following link.
This link suggests using Wilton's food colorings as for cake decorating and painting/coloring the mellows.
An additional idea I had, was to use some edible glitter and cover some or all of the "bottles" (marshmallows) with the glitter while still wet with paint.
Another note would be to try using toothpicks inserted 1/2 into tootsie rolls and other 1/2 into marshmellow to keep them together a bit better.
Such a fun and adorable idea for any girl's (big or little) party. I know they will definitely get a kick out of it.
p.s. I guess my only problem with this adorable idea is (which anyone who knows much about me - they already know the problem) would be not to run out of tootsie rolls before completing the crafty treat. lol!