Below: After less than 15 seconds in the sun, not only do you see the mess around my nails that I couldn't see before coming outside--ha, ha!--, but the stamping image shows up.
This was just a very quick look I did, but I can imagine quite a few of the possibilities using Trick-or-Treat. If you have an image plate with Halloween themes, you could paint your nails orange and then stamp Trick-or-Treat over them. I wonder how this would look if it were sponged over a lighter shade? A French tip over green or orange for Halloween, as a base color then Konad stamped with black...lots of potential for this shade. It's not a color in or out of the sun that is specific to Halloween, so it isn't limited to just this season.
Can you think of any good combinations, ideas or designs that Trick-or-Treat would work well for?